Why do you trying to give AT nade to a Tommie squad? They will be too much versatile and dangerous. Huge risk for making them too strong with double bren and bolster - aka another OP unit.
Choosing between bolster/nades/bren/AT nade - Why making this game more complicated?
There was a good idea to give them to sappers available after a grenade upgrade in HQ.
If you wanna make it unique (which i will always support) give them not a snare AT nade but stun nade vs tanks. Something like a target weak point used to do or new implemented USF mines.
