ORIGINAL: pizza
I have observed this mismatch using separate channels and no y harness also. when you show up for imac contest put a piece of scotch tape accross the gap joining the two halves but leave some slack - they will have to allow it and you will get all your flights on one charge. airplanes with ganged servos get up to 40% less batt performance.
I guess that would be up to the descretion of the CD. I am a CD and would allow it but I'm not so sure all CDs would.
On my 40% Comp ARF 260 I use 2 servos per aileron, 3 rudder and 2 per elevator. The ailerons and rudder use SF Equalizers while the elevators have 5955s that are programmed. I can get 8 flights and under a 1.5 amp load my batts read 7.3V typically. The RX batts are dual Fromeco 4800 relions. I do have a tough time beleiving a 40% higher draw with ganged servos. Im am sure that it is higher than your setup but how on earth did you come up with that figure.
Shawn