A better way to do this, rather than simply neglect all players under a certain threshold, is to compare a player’s global stats to how they perform in a given vehicle. This is what’s known in other games as a winrate curve.
Here’s an example of a vehicle that’s more or less well balanced:

As you can see, lower skilled players tend to perform worse than average, while better players perform better than average. Counterintuitively, this indicates a well balanced vehicle, as it indicates that the vehicle is not so braindead as to play the game for the lesser skilled, and that it has advantages that allow skilled players to do well. While it would technically be more balanced if it were a completely straight line, some variation is expected if we want vehicles that don’t all perform identically.
Here’s one for an unbalanced vehicle:

As you can see, the line is solidly above the average of players all across the skill gradient, and particularly for more skilled players. This is a textbook overperforming vehicle. You can imagine a corrolary curve under the average being an underpowered one.
This system is better than just looking at any arbitrary stat alone, since it can give you more information as to why a vehicle is performing the way it is.
If it’s overperforming with lesser skilled players but averages out as you get higher, that’s a vehicle with a low skill floor but a balanced skill ceiling.
If it goes negative at the higher skill levels, that indicates a low skill ceiling, implying it’s a one trick pony that’s easy to play but also easily countered and with low potential. Looking at you, Zeros.
This holds for vice versa too, a high skill floor vehicle would have lower than average low skill performance, but average to higher than average high skill.
Of course, this all implies good faith analysis from the only people who have these stats, which is probably too much to expect. They’re a business whose model thrives on frustration and the percieved advantages of spending money. A perfectly balanced game goes against their monetary interests.