So i did some looking into it and found that The american T58 had a prop turret and a full hull since they added it like this not being fully completed and even canceled for production why shouldnt they add back the coelian flak (the real E100 since there was a full hull completed if i remember correctly) the tiger 10.5 the (sturmtiger since if im correct like 4 were fully built and used) so if they add veichles for other nations that werent fully completed then add all the others to germany aswell or atleast add them back for events again to get
Iirc E100 was reserved for tournament prizes, Strumtiger is an event and will return in SL crates, Cocelian turret was a mock-up but it was fitted to a functional hull so I agree there and the Tiger 10.5 was a unhistorical mishmash of multiple planned variants.
As for the unfinished rule, it’s been around for years for air, ground and naval for plenty of nations.