The only thing coming close to this is UKF that has much better inf in cover, much better MGs, double LMGs and a light tank. I don't see any cons for the Brits except a sniper that arrives later and immobile Mortars.
The main inf is better and also gets great LMGs, the engineers are better than pioneers. A Vickers will win against a MG42 with usually 4 to 0 models in a building fight, the mortar fires double rounds and the Bofors is Satan himself. Even PIATs are pretty good right now when blobbed, which is no problem as UKF. The Cromwell is a better P4 and crushes like the first of God himself. Centaur is only a bit worse than a Tiger.
For me UKF = a better Allied Ostheer.
I know I am an Axis fanboy but I don't see the sense in buffing Allied late game without any Ostheer compensation.
In general, UKF has units that are situationally better than Ostheer ones.
- Tommies may be better than Grenadiers but they're also more expensive and rely on being stationary and in cover. A Tommy has 83/128% (min/max range) of a Grenadier's DPS in cover and takes roughly 88% of the damage from small arms fire (without their cover bonus).
- In addition, Bren long-range DPS is worse than Grenadier LMG-42 long-range DPS both absolutely and as a percentage increase in squad DPS (Brens increase Tommy squad DPS by ~43% while LMG-42s increase Gren squad DPS by ~77%) meaning Tommies pay the same amount for less. This isn't a call to buff Brens, it's simply pointing out that Tommies don't benefit from LMGs quite as efficiently.
- The Vickers wins in building fights because it simply has more DPS and the MG-42's greater suppression never comes into play.
- The Mortar Pit mortars have more DPS than an Ostheer mortar together but have less individually while costing 5/3s as much. Two Ostheer mortars also have more tactical flexibility.
- The Bofors could do with a health reduction and a range reduction on its barrage.
- PIATs could do with having their scatter removed, maybe accompanied by a cost increase. The current scatter values make it better to use attack-ground than an attack command (unintuitive micro for micro's sake).
- The Cromwell definitely needs a cost increase and a possible reduction in crushing ability.
- I don't quite understand the Tiger/Centaur comparison.
In general, I'm not a fan of balancing for early/mid/late game advantages because (depending on teching speed) one timing will always be better than the others.
I think Ostheer could be improved with a little more attention to infantry veterancy (improve medkits, give Panzergrenadiers part of their received accuracy bonus at vet 1 etc.) and teching costs but their unit roster isn't the problem.