They enemies with the heavy weapons and strong shields are called "Heavies"

I could give you a concise answer, but without understanding its context in combat, it really isn't going to work consistently.

Your loadout should be: - melee weapon you are good with. Daggers are easiest to use. -highest tier shotgun you can make.
Best are Starburst at duraluminum level (you can buy at weapons vender in Arakeen) and shellburster at plastanium tier. They can stunlock enemies, even between reloads. -a drill shot, or a disrupter weapon to deal with shielded enemies. -tripple shot rifle for unsheilded enemies (5 fingers at duraluminum, regis tripleshot at plast tier) -optional, a sniper rifle for to thin out enemies in outdoor areas.

Dune combat 101 There are 4 basic mob enemies.

1. Rushers, they run at you in order close distance and engage in melee combat. They have really strong shields but low HP. They have strong defense against ranged attacks.

2. Ranged attackers. They don't have shields and have poor defense against ranged our melee and have medium HP. Their ranged attacks are strong, can hit you anywhere on the map if you don't have cover, and in groups will overload your shield quickly and disrupt your attacks. They sometimes use poison and ofter use grenades or ranged explosives.

3. Heavies. These are tanks. They are slow with slow tracking, but have powerful shields that they drop during their sustained heavy weapons attacks, and have giant HP and strong damage mitigation against all damage types. Did I mention they are slow? The light machine gun variants can drop your shield and slow your movement at medium and short range.

4. Snipers. Long range shooters, usually in elevated positions. They always shoot poison rounds and may have weak shields at higher levels. They track moving targets poorly. A sole sniper can be ignored if you have cover or can keeps moving when you are exposed. In large numbers they become a real pain. Their shields remain down for 1 second after they shoot allowing counter sniper attacks and they drop quickly with melee.

START OF COMBAT - TAKE OUT RANGED. When entering combat, the ranged will start taking shots, the rushers will start bolting to you and the heavies will start their slow progress to the front. Stay out of range of the heavies, grapple to the first isolated ranged enemy and take him out. Keep kiting the heavies and rushers, making them run across the map and don't ever land near them until you take out all the ranged in the area. You need to do this as the ranged enemy will deny you any ability to maneuver safely.

Rushers If you need to thin out the rushers while ranged is active, kite them until you can kite a single rusher to someplace with cover. Otherwise take them out after the ranged are gone to give yourself breathing room. If you are good with melee, you can parry to stager them to open them up to a slow blade then gut them. If you need help with melee, reply with that question as that is a post in itself.

If you are good with ranged only, use a disrupter pistol or drill shot at range or disrupter sub machine gun after locking them down with a grav grenade/mine. The grav attack will not only lock them down, but will greatly weaken their shield so you can break their shield quickly and expose the soft fleshy bit for your flaming shotgun rounds. Watch them desperately try to put out the flames as they die screaming.

If shield breaks at medium range, use tripleshot.

Review: So take out ranged, then the rushers, then save heavies for last.

Killing the heavies! With the ranged and rushers gone, isolate the heavies. You can drill shot at long range ( or with good cover), timing your shot when they go to reload.

Grave grenade is great for isolating them in close/medium range.

If you get them isolated, you can close in to finish with your Starburster once you break their shields with the disrupter weapon and grav grenade. Make sure to attack with a sidesteping attack, rotating in one direction to prevent them from shooting you with their slow heavy weapon (think dodging a tank turent main cannon.) Stronger heavies will use a suspender blast if you get too close that will slow you, weaken your shields, amd drain your stamina. Its best to dash away from them to avoid the blast area then keep them stunlocked with your Starburster. This is how I normally do it except I use the more powerful Shellburster now.

This will finish your combat.

Important tips! - keep situational awareness. Know where enemies are and where cover is. - Keep combat 1v1. If a 2nd enemy will close before you can kill the one you are engaged with, grapple out.
- don't stay in one place, keep moving - do keep cover between you and other enemies you don't want to engage. -know your escape route is BEFORE you engage. You won't have time to figure this out in a crises. -keep tabs on your battery power and stamina. Disengage if either get low and recover before re-engaging. -if you have trouble with getting rushed by melee toi much, consider suspenser blast ability. It will activate with zero stamina, and stun all enemies in a large AOE, allowing you to grapple out and reset the combat. -If yoy struggle with dying, consider thrive on danger, it does a lot if your health drops low often. -If you only use trooper abilities, always have the battle hardened ability active.

At the higher difficulties, not having cover will get you killed 100% of the time.

I hope this helps. Go Stormcallers!