It seems very logical to slightly help ost with repairs. Its not going to be a gamechanger but a useful detail that may tip the balance in the right way.
In regards to team games I don't think the balance needs to tip any further that way.
Soviets suffer from the same issues so I go repair stations if I really need faster repairs. Con repairs might be more useful if cons are better with the coming patch.
USF tanks take damage more easily/have a low hp pool so a slow repair time would cripple them and further encourage spamming TDs.
UKF-Once you invest in bolster, anvil and the munitions upgrade for the RE then they repair quickly that much is true. But their engineers are also tied between keeping emplacements up (if you're daft enough to build them these days) and repairing their only relevant tank which is the Churchill.