Sucks !
This has nothing to do with ROTS EP. 3 . The X-wing didn't exist till the Rebellion.Here is a article from Star Wars.com : "The Incom T-65 X-wing starfighter has become a symbol of the Rebellion's starfighter corps. Pressed into service time and again, the typical Alliance X-wing shows the scars from previous engagements, though the fact that it still performs as an advanced vessel of space superiority is indication of the ruggedness of the craft.
The sleek fuselage of the X-wing starfighter is 12.5 meters long. The long, narrow spaceframe is flanked in the aft quarter by four massive realspace engines. Each engine has an aerodynamic S-foil mounted on it. The wings not only serve as stabilizer surfaces in air travel, but also distribute deflector shield energy and serve as weapons mounts. The surface of each S-foil bears squadron and fighter markings.
Located midway through the ship is the X-wing's cockpit module. Behind the X-wing's cockpit is an astromech socket. The astromech droid provides astrogation data for the fighter's hyperdrives, and serves as a co-pilot and technician during flight. Three landing gears extend when the fighter is docked. "