Evening troops.
I'd go back to the Falklands conflict, 1982, and get Col 'H' Jones VC to duck, rather than getting slotted in the back by that Argie MG position. I feel that British military doctrine could've gone in a different direction if 'H' had survived. We use Manouvrism, which I think 'H' would've advocated, but I feel a more 'fire-power and aggression' doctrine may've evolved.
Failing that, I'd go back to Agincourt; not to change the result, 'cos we won. I'd just provide the Welsh Archers with mortars and grenade launchers - just to make the victory all the more decisive...!