Hi Sailor Steve,
thanks for your comments! I agree with you that the man on the left looks fine. However, I don't think the one on the right is standing on an elevated platform. Aren't the two boards at his leg (at his knee and below) the platforms?
I also think that rescaling the crew members is not possible without a huge amount of work. At the moment I am just interested in what might have a wrong size/scale. For me the crew looks strange on the IX turm

Given that blue prints of the IX exist, I doubt the sub has wrong proportions. Maybe a 3d guru might shed some light on it.
Anyway, as long as no one agrees about what might be off, there is no need to think about who will do what

BTW, who do you refer to as 'they'?
Cheers, LGN1