AEC is worthless against infantry now and Commandos camouflage has been nerfed. Why do you think Brits are stronger?
Because the PIAT change covers the Brit's biggest flaw, defense against light vehicles. Before, the AEC was necessary to counter them which set the Brits back significantly in fuel and kept their teching in check. With the AEC being meh and PIATS being reliable, there's nothing stopping Brits from rushing early armor and effectively skipping the part of the game where they're supposed to be weakest. On top of that, they got away with most of their cheese intact. Comets are still crazy OP, Cromwells are too cost efficient, Tac Support is still nuts and so on.