As suggested elsewhere...
Instead of ENY, modify downtimes according to team player numbers:
Bish 100, Knit 70, Rook 50.
Bish kills Knit ack, downtime = 70/100 * 30min = 21 min.
Bish kills Rook ack, downtime = 50/100 * 30 min = 15 min.
Knit kills Rook ack, downtime = 50/70 * 30 min = 21 min.
(Rook kills either Bish or Knit ack, downtime = 30 min.)
This would give relief to the low-number sides, without denying anyone their favorite ride. It is also proportional to the numbers imbalance, rather than arbitrary, as are ENY values. It still gives strat bombers a role to play, and won't deter a horde, er... organized strike.