Well, they were 37mm in Poland and France, so hes sort of right.
Anyway, I stand behind this suggestion. Though the loadout should be something like this:
56 HE
10 HEAT
I don't think there should be any standard AP shot, since that just encourages people to use it against other tanks. The HEAT shells are more than sufficient for helping kill mattys and valentines, but otherwise, you should be spamming HE with these tanks.