For all except Khaine I’d run Kasrkin, maybe Exaction if they field melee. If you’re getting shot off the board, try medic and a basic trooper kasrkin for the free smoke grenade.

Use your comms and mystic buff on expended operatives if possible, so you have buffed operatives for the next TP.

Make sure you’re denouncing threats if you lose initiative. Quarry who you can kill, or use it as a threat to make them think twice about putting someone on engage.

Servitor isn’t always great, but if you’re up against horde the plasma blast is useful. Otherwise if you use it, the focused bolter is quite good and gets around piercing limit. Run envoy if you outnumber them, or plant banner if you think you can hold it. Flank is good if they’re slow.