The rebellion is poor, and most of their command structure was small enough it could fit in one base (village) on yavin.
The imperials (bandits) outnumber and overwhelm the rebels and kill off a massive number of pilots (seriously, a significant number of pilots in our game are dead.)
Throw in the incredibly obvious sword fighting that occurs (however limited) and it's not hard to see that George Lucas basically combined the hero's journey with some decent samurai movies.
You're reaching here..
Those that died at Yavin, were not main characters... and therefore insignificant to this.. the Empire is not a bandit gang, and remain the main aggressor in the following movies..
