Intriguing title LoL
FWIW, my views are that in general A/c units should be costed between 75 and 150 each (giving formation costs between 150-300 for two, 250-400 for three). Also a general guide would be to add 25 points to the cost of the first 2 units to cover the 'activation advantage' (hence the TBolts cost of 175) and ideally the formation costs should aim at 200+ to minimise the potential for spam. They should only field 'moderate' weaponry so that the air formations do not have too great an impact on E:A as a whole. This is why ranges are much reduced from any ground-based equivalent, and often the stats are also reduced. Finally, the Eldar units should be the 'best' in the game so the stats of other air units should never exceed any individual stat, and usually be worse for several individual stats.
I realise these are very tight constraints which are necessary to counteract power creep that raises its head with almost every new unit / formation. Hence the need for this discussion with the
Avenger.
That said the current
Avenger stats don't seem too bad (though 150 a pair seems too cheap) as they fall roughly with the above guidelines, though I have not seen / heard of any play-tests.