1) KV-1 says hi, outdated unit is what makes SU.
2) Still better than Valentine.
3) I'll take Jeeps over UC anyday, that thing can't turn for crap, can't push inf, MG still shred it to pieces.
The KV-1 is a different matter entirely, it was part of a doctrine before the times of WFA. As for the M3 Lee, we have to take into account that the British and the USF don't need this unit since they have their own medium unit which is good enough.
The Matilda would just be having the same role as the Churchill, but it would be doctrinal.
As for the UC, it can counter garrison units with a flamethrower and be selected as a command vehicle compared to regular jeeps since it can survive.