OP this is your first post so I will be a little gentle, but please spend time playing all factions before jumping onto the balance train suggestions. It takes an enormous amount of knowledge and skill to balance these factions.
Brits are bad for gameplay in many ways but they are also not just getting buffs across the board in the next patch.
If you need help with strats go to the state office and the faction you are looking for help with.
Everything the brits have is better, if not by stats then performance.
Comets>Panther in both cost and performance
Cromwell>P4 in both cost and performance
Bofors>everything below P4 in obth cost and performance
Mortar pit>every other Mortar in both cost and performance
6 pounder>all other at guns in both cost and performance
OKW had it's teeth removed a long time ago. Remember Obersoldaten when they really were Ober. Bonus to hit retreating units, free mg, and could fire on the lmg on the move.
I'm trying to be objective about this topic but playing double brits in 2v2 is not fun at all.