I would buy a short servo extension cable, about 6" maximun. CUT THE RED WIRE IN IT. Now you have no risk to the other ESC's pins or UBEC's cable or pins. This is a standard way to deal with the 2 electronics units fighting each other. 1 UBEC SHOULD be more than enough for most normal sport planes and their servos.

You do mention they are LINEAR ? They MAY not handle a bunch of servos. Could you post the data sheets of the ESC & UBEC ratings ? Then we could tell you more accuratly how many of the actual servos in your plane it can handle...........Some BEC's are VERY limited.

Post back. Get the BEC too small and crashs do occur from that.

Rich