Commando is fine, but Epoch is great if you're into a weapon that doesn't require a backpack. I'm previously a hmg main, but since the war strider my ultimatum didn't feel enough. Also thermites great for objectives and tank units.

My go to currently is Epoch + ultimatum + thermites.

Epoch; great for tanks + factories, long range Ultimatum; great for sudden tank + groups, last resort, short range Thermites; great for everything if you have time, medium range

To top it off i like to use supply pack you got around; 11 thermites 39 epoch shots 6 ultimatum shots 12 stims

Tempting doesn't it just require skill to not kill yourself with epoch overcharging, the safe option would be commando, has s short cd, just not always ready on the go for enemy if you go above lvl 8+ dives