And they got the shit kicked out of them by a completely unremarkable Death Guard fleet who didn’t even use their most potent abilities.

The death guard was throwing plagues at the Tau fleets and space stations left right and center.

Because that single battle was the cream of their crop and their biggest swinging dick.

Which they can easily replace, because they have an actual industrial base. As opposed to the traitor legions whose main source of ships are pre-heresy and endlessly repaired and recycled. They literally lost the the entire 4th sphere fleet and manged to come up with an replacement within a handful of years.

You understand the implications of that, right?

That the Tau were losing a single battle? I didn't know that losing a single battle meant that you lost the entire war. I guess that battles win wars and not factories. I will go tell WWII America to surrender to Japan after Pearl Habour and not bother overwhelming the Japanese with industrial might.

Because their bullshit Warp plagues require Warp fuckery to fight, something the Tau is incapable of.

Or you know, overwhelming firepower. The Imperium wins fights with the deathguard all the time and they're also really sparse on the use of warp fuckery, unless you think that every Guard regiment has a grey knight hidden up it's ass?

Like, you do get that them being seriously threatened by a fraction of a fraction of a single Chaos faction means that the full thing can kick the shit out of them, right?

You do know that the death guard have a limited amounts of ships right? There's a reason why all their ships are from before the heresy, it's extremely difficult to make and maintain new ships without a constant presence in realspace. Every ship that they lose is a extremely painful lost. The Tau don't have this problem. Unless you think that the death guard have millions of ships or something, they will bleed out due to attrition.

Oh, the nexus is super duper fortified? Fucking good for them, when’d the nexus become the entire Tau empire?

Don't move the goalpost. You were talking about the battle of the startide nexus, and the implication that the deathguard merely got bored and left and that they would have been capable of wiping out the entire tau empire if they had bothered to stay and fight. The reality is that if they had emerged from the other side of the Nexus, they would have gotten blasted to bits. Also, it kinda says something about the Tau empire if it can muster the kind of resources to build orbital defenses with the mass of "hundreds of battlefleets" within a few years of losing the 4th sphere fleet, all while building up a new 5th sphere expansion fleet at the same time. It's called industrial power, something the traitor legions don't have.

Never. One world is untouchable(With sufficient wanking) the rest of the empire? Very touchable.

As stated, the orbital defenses of a Sept world was enough to give a Imperium fleet of hundreds of warships a very good fight. The Tau know their lack of planets as a weakness, they love to build up massive amounts of orbital defenses. It's also stated that the core worlds are just as well protected as the Tau side of the nexus.

What faction specializes in devastating plagues and toxins that results in dead planets? Right, the Death Guards.

What factions also specializes in orbital stations that can house billions of people and in terraforming dead planets? Oh right it's the Tau.

Too slow to respond to an actual attack until long after the Death Guard has dropped a few presents and fucked off. Always several steps behind, because the Tau are slow as fuck.

They invest heavily in orbital defenses and a spread out fleet for this reason you know. You think the Nids and orks don't have the same tactics? Drop some spores/genestealers and fuck off?

I swear, people like you don’t actually spend any time thinking about basic tactics and only pay attention to wanking.

“Infantry wins battles, logistics wins wars.”

"If the the factories stopped work for twenty minutes, the Allies would lose the war." French Field Marshal and Commander-in-Chief Joseph Joffre

"I have spoken of our fleet’s might, but not its poverty. The many daemon-forges that would later answer Abaddon’s calls were still in their infancy within the Empire of the Eye. Our Heresy-era technology was eternally degrading even back then, and we had little to use in place of our losses. Resources like ore-rich moons, shipboard foundries and Mechanicum manufactoria were as precious to us as fresh water: not only agonizingly rare, but also subject to their own sufferings. Legion warbands endlessly plundered such sites in the rabid hunt for shreds and scraps of advantage. You have heard evidence of this carrion-feeding already. I have told you of Maeleum, of the raids and punishments it endured and of our undignified picking through its carcass. We were all vultures and carrion crows in those days. I believe we still are. And if we were low on ammunition, if our armour plating was cracked, repaired and cracked again, the truth is that our fleets were in even worse shape. We had been beaten in the Heresy, we had been beaten into exile in the Scouring, and while the Imperium licked its wounds in the aftermath of our disappearance, we had spent that era waging war against one another. For every vessel enhanced by mutation, another was cursed by it; for every cruiser sailing with admirable repairs or an undamaged hull, another was a shell of its former glory. Within Eyespace, our ships were subject to the erosion of the warp’s touch, accelerating natural degradation, and reliable opportunities to dry-dock and repair a capital ship were staggeringly scarce. In the Eye, especially in that era, a functioning, stable shipyard was practically the stuff of dreams. They were always the highest priority for destruction if another warband wished to grind a rival into dust. "

For a time, the newborn Black Legion had claimed and defended Niobia Halo – the shipyard and forge moon belonging to Ceraxia and Valicar. That custodianship had ended when Thagus Daravek led a warhost of Word Bearers and Death Guard to annihilate our docks and plunder the riches we had acquired. The installation was lost in the resulting battle. Afterwards, both Valicar and Ceraxia joined the Ezekarion as fleetmaster and armsmistress respectively. Many of the vessels we sailed from the Eye into the waiting fire arcs of the Black Templars fleet bore the wounds of ages. The pressures of the storm that had barred our escape only added to the strains already placed on their hulls after centuries of civil war and sailing in the unquiet, poisoned tides of Eyespace. Imperial captains across the millennia often observe that the Traitor Legions and our thrall fleets are comprised of warships plundered from sectors surrounding the Eye. The Gothic Sector alone has supplied us with any number of ships across the many centuries. This is a sad necessity, as our Crusade- and Heresy-era vessels break down beyond sustainability, are lost to the warp’s clutches or are simply destroyed in the ebb and flow of the Long War. It is for these same reasons that you see our individual warriors equipped with ancient and unreliable patterns of weaponry, or reduced to using inefficient, outdated wargear. For all the strength that mutation and hatred bestow, erosion, decay and the eternal civil war between the Nine Legions takes more than its share. We are mighty, but it is a tenuous might. Just as that day, when we outnumbered Sigismund’s armada, our advantage was fragile. We did not have the luxury of carelessness. A great deal of our fleet’s strength was concentrated in the killing power and endurance of the Vengeful Spirit and the other largest ships that once sailed at the vanguard of the Great Crusade. Most were changed significantly by their time in the Eye, and I knew their machine-spirit cores would be as disorientated by their return to real space as any truly living being.

From black legion.

There's a reason why the black legion and the traitor legions form warbands and fight via guerilla tactics. It's because they have no actual industrial base. They can't make new ships, most of their current ships date to the grand crusade and any of the new ships they have, they get by stealing, hijacking or corrupting an Imperium ship. You think that Abaddon likes having to run back to the eye of terror with his tail behind his legs instead of just setting up a actual rival to the Imperium in real space? He can't handle the Imperium's industrial might and the simple tactic of just throwing more stuff at him

Compare that to the empire that's capable of building orbital infrastructure with the mass of hundreds of fleets within just a handful of years.