Tl:dr- No point comparing the two- compare them in their roles. Survivability differences are there to balance their effectiveness relative to opposing factions, not to grant attribute equality to both sides.
This was the best post in thread.
@nullist ostheer weaponcrews have less models, no denying. Why? Designchoice. Why? Ask relic. Not satisfied with the official explanation? Contact them and or get them to explain it in this thread and or on their twitch stream. Think you made your point by now.