The Difference Between Ryder and Ryder

Their backgrounds won't affect the gameplay. At all. No locked doors or differences in combat effectiveness. I think we just get a few unique, easter egg dialogue. Scott will likely talk about his time on Arcturus Station, watching as the human fleet launched the attack against the geth in ME1. As for Sara they might tie her to the salarian excavation team with the hanar protesters (elevator news ). Or if the AI is her first multispecies job maybe initially she was to be assigned to the Eden Prime researchers but was injured/doing something else/on shore leave at the time so the Alliance sent Ash's unit instead.