Fenimnis,
This layout will work, but only if the batteries are a matched pair. Otherwise, Tramsgar's right about the serious risk of turning your airframe into a smoking, flying firebomb.
Assuming you're wiring this up for FPV, it might be simpler to go with one huge battery running everything, or one large battery for motor/servos and one small one for the video tx.
The only advantage to paralleling batteries is building a battery size you don't have with ones you do. Since Lipos are a consumable item in RC (yes, they can last a long time, but batteries wear out faster than anything else under non-crash use :black_eyed
, IMO, paralleling should only be a stop-gap measure to get you in the air until you can afford & pick up that larger battery size.