Is there any real difference between them? My concern mostly about energycells vs heat. i feel like i can use more abilities and keep max regen on a commando then i could on a merc.

So your answer for operative and snipers being hard to kill is to make the sentinel have even more cc breakers have the highest damage(uninterrupted) and have a gap closer that goes through entrench. That doesn't sounds unfair at all.

sorry moved the classes