I still think you could do a matching set including the best medium and heavies available for the four that had them and for those that didn’t… (i.e. Japan & Italy) a medium-light (M 15/42 & Type 97 Chi-Ha) and a medium (P 40 & Type 3 Chi-Nu or Type 4 Chi-To)
Alternately, the Medium + Medium Tank destroyer might make sense. That would be my second choice, I think (after the Medium + Heavy option.) I guess I just always prefer as much logic and consistency as possible…