Remove section cover bonus, make sections 5men regardless of Bolster and balance them around them being 5 men, give sections snares, remove sections trenches, remove sappers snare, put UC in T1, nerf the shit out of the AEC, nerf hunt, put mortar team in T1, put every UKF emplacement in Advanced emplacements doctrine, remove phosphorus rounds from Comet, put land mattress in T2 and make it a useful non cheesy unit.
Anything less than that is not acceptable. Better have a dead Brit faction than an OP Brit faction.
Instead of removing and nerfing and everything why not just instead put them behind the Hammer and Anvil sub-doctrines?
If you want more mobile gameplay, choose Hammer, if you want more static and defensive doctrine go Anvil.
Example, instead of T2 they're moved to the HQ as choices there. With the weapon racks being kept as a 3rd upgrade of course.
Hammer gives you 5 man infantry squads, grenades and snares, mortar team, AEC, Comet and the rest of the Hammer and more aggressive and mobile oriented abilities, upgrades and units.
Anvil will instead grant you access to trenches, sandbags, cover bonus and so on but your infantry is kept at 4 men instead but they're a lot tougher in a defensive position and grenades. You will also get the emplacements, Churchill and so forth. It could also maybe give medics to your HQ and FA as well? Or engineers.
Stuff like the support units such as MGs, Snipers, AT guns, the Cromwell, Crusader and Firefly are kept as is and are accessible without any sub-doc choices.
This way the original concept of the British is kept without removing anything, you're just giving people more distinct and clear routes in which they can choose to play with.