There were graphs presented by relic recently in regards to 1v1, you can see dominance of OKW and under performance of UKF.
This means that only small changes, mainly to these two armies are needed now.
What causes them? For OKW, its definitely the volks and shrecks, late game was toned down, but early game is still extremely potent.
Brits on the other hand, early game is pretty alright, you still need to rush T2 for snipers and T3 for armor, but it is late game where they start to slow down, despite them being in theoury the bridge into allied late game with now nerfed, likely overnerfed churchills and overall hammer/anvil based choices and builds, but I don't have as much experience with brits, so that is my guestimate from playing alongside and against them as well as from watching the streams.
remember that those numbers are old now.
according to newer numbers, the balance is better than it has been at least since brit release:
with a few tiny tweaks to OKW, UKF winrates will go up slightly as well (and remember, UKF play rate is way lower atm anyways, so UKF winrate is the least reliable value in there) most likely.
since i don't play OKW at all, i can't really comment on what is the best way to go, but from community consensus and watching streams i'd say it's volks vet and/or the early capping power (so number of volks early and kübel capping) that should probably get tuned.