This is i think pretty straight forward. And it’s especially horrible fter sales. A completly new player creates an account, and immediately buys a rank 6-7 premium, and goes into a match, while knowing absolutely nothing about the game.
These players just ruin the games of every player in that match.
Not only that, but then, they discover the tank assault mode, and make it absolutely impossible to win any match, because they are just constantly dying, popping smoke everywhere, and getting zero kills.
Here is a great example:
So i suggest to either not allow players to buy a premium vehicle at a BR range, where they have no tech tree vehicle unlocked at the same BR.
For example, to buy the Leo 2 (Pzbtl 123), a player would have to have at least a single tech tree vehicle unlocked at 10.3
A second option would be to allow them to buy it, but not allow them to get into any real pvp or pve matches, until the smae condition is met that i previously mentioned. They should have the ability to play custom matches in it, but not AB, RB, Sim, or assault modes.
This could also help against bot accounts using high rank premiums, since they would need to grind out a similar BR tech tree vehicle as the premium they are using.
EDIT:
If you have a rank X vehicle in a tech tree, you should be able to buy/use a rank X premium in other trees.
EDIT2:
Another way could be done, that is similar to the “join already active matches” option in the settings.
If you turn this new option off, then you would not be matched with players at a BR, where they don’t have a TT vehicle.
For example, you want to play at 9.0 (let’s assume you would get a 9.0 game) with this option turned off, then you would only get to play against, and with players that have at least a 8.0 tech tree vehicle.