I don't think it's outside the role of the balance team - they just need a model that allows them to see where those units sit in relation to each other. The data for the units is the easy part, hard simple numbers - it's the performance relationships between those factors that describe the 'curve' of air units in general - and that units sit on or near that curve, is what will bring balance.
The problem is really quite simple, without that kind of relationship model, you just have pure fantasy - so any argument about X does this and Y does that - is completely circular. Adding a bit of E there, or shaving one value a bit, doesn't change that discussion, since any one change may shift the curve of several important metrics.
As the most simplistic basis - I'm sure someone has built a table showing how much firepower (DPS) you get for Resources expended (Mass and Energy). It's an important indicator that you've got a generally smooth cost transition from unit to unit - versus DPS. If every other factor about the unit was equal - that would be relatively balanced - but there's more to it.
You have to somehow quantify those other differences, such as the relationship between mass, HP and speed - an especially important one for air units. Again, the mass/HP/speed relationship is a metric that helps you assess balance - but only between like units.
This is just an example of how complicated balancing can be. In the end, you end up quantifying just how much speed, a bulked up fighter can have, with a given weapons package - and how much additional E you might need to spend on that unit, to bring the combat speed back up to a point where it can tangle with a much lighter air unit.
In the end - it's really the difference between magic and science. A lot of good points are made in these discussions that want to head in that direction - but never quite make it there.