User blog comment:James12708/Possibility of a Mass Effect 4/@comment-118.210.61.141-20130204152701

If they were to go to events prior to Shepards story, earth/humanity would be treated too poorly by the council races to appeal. Events post Shepards trilogy would have way too many variables from the choices made.

So for both familiarity/sense would presume that whatever story they chose to do next(That is if they chose to make a Mass Effect 4) would have to be aligned with Shepards time period.

Theoretically between 1 and 2 there are two years where he wasnt around, and a while between 2 and 3. For the entirety of 2 he also wasn't directly affiliated with the alliance.

Therefore, I would personally consider, if i were writing the story for the game, Having a secondary alliance hero type guy surface during shepards absence.

Or

Make the character start as a mercenary or living in one of the terminus systems or something similar with no affiliation to military, the council or anything really to do with shepards world. This way you get the feeling you got from the first game when your character initially earns spectre status. Also, some people might prefer to play as a different race. This way starting as a Mercenary etc. You aren't stuck as only being human. This opens up a lot of questions. Race specific powers for each class available, Your eventual crew and their reactions playing out differently depending on your race.

Sorry for pretty much writing a small essay.