According to series art director Amy Beth Christenson, the First Order X-wing drones are pared-down replicas that the First Order TIE pilots use for practice. These drones have no cockpit, and feature a few nods to early Clone Wars-era designs, like wings similar to the ARC-170, and some visual cues to vulture droids.
Lt. Galek was named 'Lt. Jimes' in early drafts.