I personally I am not a big fun of 6 men squads lets leave that for soviet as stock...
My personal opinion is that UKF is one of the worst design factions. A decent solution I see would be to take advantage of the hammer anvil design and offer to paths of UKF for each stage of the game. Either defensive units closer to Ostheer design (4 men squads with LMGs) or offensive units close to USF design (5 men squads with BAR type of weapons). Similar with tanks.
In addition to more option on how much one can invest in emplacements both in tech and cost.
Finally UKF stock units that semi elite infatry could get some sort of upgrade with hammer/anvil. For instance the 4 men squads an officer with Pistol/Smg that increased the durability of the unit without increasing the Far DPS or some sort of timed ability for 5 men squad increasing RA or DPS for 5 men squads.
So, following your feedback. Infantry sections will still stat with 4 man, i'm ok with that.
Now if we let them stat with 1 weapon slot, then anvil will add the 2nd slot and give them survivability upgrade like armour/RA to become ober equivalent, and, hammer add 5th man and change their only bren to elite bren profile - aka fire on the move, the 5th model will use a sten or Thompson.
What's about that ?