Random thing why don’t they ever give skins to the last tank? I want it on a tank I’ll use more than a few hours I want it for the m3 stuart or something.
They did a year or two ago, Rhino skin, some other M5 too, maybe devs will readd…
Rhino 
It wasn’t a skin, thought, but an entirely new stuart. It came with more potent shells.
I still use it to this day: because fun.
Need a HA GO skin
Because these drops arn’t skins, they are technically separate vehicles and giving out an endgame one might screw with balance a bit.
If those are only available to later tank squads there shouldn´t be a problem. I just recently realised I had a P-47 from a Twitch drop for the A-20 squad but it has M8 Rockets instead of HVARs
That’s not a Twitch drop, that’s an event vehicle. Twitch drop vehicles are identical to campaign vehicles except with a unique skin. Event vehicles are more unique, with different payloads like the P-47D-22-RE or the M5A1 Stuart Rhino, or just outright different vehicles from campaign unlocks like the Fw-189 and Jagdpanzer IV.