The vehicle spawns in BTB are already bad enough, but adding asymmetry to them just makes the game hilariously unbalanced for the team getting better vehicles. Getting an extra wasp is basically a free win in most games, and the same is true with tank and wraith spawns - they’re vehicles that take coordination and effort to take down, and can allow a team to immediately snowball in to winning the game.
Above and beyond the garbage that is the random vehicle drops in the first place, and how they interact with the incredibly terrible challenge system, a system that gives a team an almost immediate free win at random should never be in a game like this.