your build of 3?
could you provide a little more details to it on how you start?
Sorry, I meant 3 Infantry sections, 1 vickers, etc.
Basically I use the vickers to support 1-2 of the infantry sections in pushes, the other infantry section caps/harrasses other parts of the map since it can handle itself against practically any unit OKW has early game when they are in green cover.
The 1-2 IS and the Vickers shutdown almost all OKW pushes before ISGs come out (and ISGs are getting nerfed so its even easier in balance preview) so you will be able to hold your half of the map at the very least.
The snipers are important because they inflict bleed and are tough to counter if you micro them well. They also will shred pumas, kubels, and other lights, and once you get them to vet 1 they will engine crit any other lights hitting the field.
Brit AT gun is basically a pak with bonus accuracy.
Royal engis just plant mines, and then once you get the cromwell you go anvil, get a 2nd engineer, and upgrade both of them as heavy engineers. At this point your army is complete and you just replace losses/build more tanks/call in tanks.