Its not a bad idea but. To stop everyone farming PvE and lowering the PvP you need a limit to the amount of PvE you can do, for example.
You buy a new high tier tank, you have stock everything. This might be ok in same tier battles but in the higher tier you are just cannon fodder. You should only be able to play PvE to research modules to upgrade certain things such as tracks, turret, engine and a better gun. Once you reach a certain point in the research ie have the top gun and can research the next tank PvE is disabled for that tank.
With that and a few adjustments it could work without lowering the PvP battles too much. So PvE for researching certain modules on tanks only.