Say for example you played Stalingrad and got the BF109 E7/U2,if you want to use it on the TT squad so you can grind it much faster you just can’t,since the only copy of the veichle is locked to the legacy squad that takes a stupid amount of time to level up.Doing this for all veichles will let such issues be avoided and might promote using some less used veichles,such as the afformentioned BF109 E7/U2.