Crew training in prem tanks

CatStalker: If you have a crew trained for a m4, you can use it in a super pershing without any penalty.
if you have a crew trained for a E8, you can use it in a super pershing without any penalty.
A crew trained for a super pershing will suffer a penalty if put into a normal tank.
a crew trained for the m4 will suffer a penalty if put into an E8