Best Double trencher infantry & UA lists

I think that Haley3 would be best.

Reposition is useless for them if you give them active combat role... so if you want to run a smoke wall you better drop the CA on one unit.

Usually, Trenchet Infantry is expected to be got charged next turn after they shoots, and as you know they do nothing while in melee other than jam the enemy(and usually the enemy will try to jam ours, not us). But Haley3 can mitigate the problem by give them DEF +2 to survive against charge attack&Ghost Walk to out of engagement and CRA again.

Maddox is always a good caster. Snipe makes Trencher Infantry much better and every Snipe casters are the good Trencher casters, but Maddox is the best because she has a melee damage buff - usually it is not a good idea to order them charge, but her feat allows them to actually crack armor. So it ia worth trying.

Personally I don't like her boring style and lack of choice, but it is hard to deny that she is one of the best Trencher caster right now - even consider Dauntless Resolve is a waste for them.

Stryker3 CAN use them because they needs no caster support to survive, but I think that there is no merit to pick him over Maddox. Although Stryker3 hits much harder, but still Trenchers under Maddox already hits harder enough to cripple a warjack, and she also gives Snipe on them.

Brisbane2 would be a good pick too. You can order them to shoot then reposition back as well as keep Dig In for one turn, after that they can either CRA again or charge with Fury next round.

Poor Haley1. The removal of -2 SPD makes her worthless choice as well as remove the title of best Trencher caster. -2 SPD debuff was that hugh for her and Trencher forces.

Although you can deliver them fast with Blaize and they needs no caster supports to survive.... without a damage buff there is really no merit to charge them and you better keep some distance to the enemy. Because they can kills the enemy at ranged well and they lost Dig In once engaged, without damage buff there is not so good reason to order them charge. Only some corner cases(such as have to kill a lots of enemy troopers, have to hold thr ground, have to stop the enemy to shoot, or fortunately, have a line of sight at the enemy caster!) would let you such a bad move.