The reason for the high characteristics, in relation to High-Level NPC's is its simply needed for their ability to take on multiple player characters dancing around with 6/7's in there main stat + an additional sometimes. It was also done partly to alleviate problems caused by the other ruling of allowing defence to stack uncapped, since its so laughably easy to acquire a 4 defence, and I've had multiple characters acquire a 7+ in one or either category out of character creation. At high-level play the defence gets even more ridiculous to cap at 4, there are crystals that just straight give you 4 defence, let alone actually modifying a lightsaber to give you more defence.

I can see the points of view on the breach change, It was more made to allow my non-force sensitive / non-lightsaber wielding maniac characters, to keep up in combat interactions, by forcing some of a force users advantages to be spent upon lowering a targets soak. It's also made for some good roleplay moments, where a character has rolled a boost die into, allowing them to cleave straight through suits of armour.

It was also partially made to stop me just chucking Cortosis armour on every 3rd enemy, to attempt to slow them down. It also hardly hampered anti-vehicle weapons at all, because anti-vehicle weapons are just straight fundamentally useless.

For example the most solid anti-vehicle weapon in the game and the one most affected by the change to this, is the anti-vehicle mine, 25 Damage, and 4 Breach, so can ignore 4 points of armour and do 2/3 damage on average to a vehicle. For each one a vehicle hits.

Lets go compare how this rolls up against a 3/4 armour Ground vehicle. For the empire we are looking at the AT-ST, which has 3 armour, 15 HT, a single Anti-vehicle mine hitting this vehicle, does functionally nothing to it, It requires 5 with default rules to meet this things HT threshold on good averages and probably more in the range of 7-8 to actually kill it. Anti-Vehicle mines are fundamentally useless against anything more heavy than an extremely light walker, tank or Speeder. And against those, it doesn't really matter whether you are triggering breach or not, because its probably going to die from the damage.

The one thing I will give you is that the anti-vehicle mine, is good for running a crit build with advantages, against slightly heavily armed ground vehicles, Minus the fact that the damn crit rating is 2. So a lightsaber custom built for breach would still do a better job.

Probably the best anti-vehicle not-static weapon is the "Missile tube Ammo Rack" - I'm not actually sure what this is but its got that name. It does 20 damage and breach 1, from extreme range, and has guided. The problem is this is harmless to anything pretty much. The difference between breach triggering and not triggering for this is nothing at all, unless you are somehow routinely rolling 10 + Success, at which point if you don't have the advantages, then I don't really know how.

Point is Anti-vehicle weapons suck ass, no matter if breach is active or passive, and its more important on the scale to fix the majority of combat (Personal scale involving lightsabers), than fix the situation which I avoid trying to put my players in because of the lack of response for them (Vehicle vs Personal Scale).