How about we think back to week 3 when the Pats started their 3rd string QB and destroyed a playoff team by 27.
How about you jump ahead a week when a 3rd string QB scored 0 points playing at home against the Bills. Brady came back a few weeks later and hung 41 on Buffalo.
Do Brady's numbers or the team's W-L results in the games he played change one iota based on what happened in the four games he didn't play? No.
We don't know what we don't know, so anyone can come up with an outcome of what would have happened had Brady played those first four games. Without him, they went 3-1, with him they probably would have gone 4-0. NE averaged 20 ppg without Brady playing and 30 ppg with Brady playing. However, other than Arizona, the teams he would have played . . . at home . . . he historically has dominated.
Over the last few seasons, Brady has lit up Buffalo for 50+ twice, 49 once, two other games in the 40's, and seven games in the high 30's. Let's split the difference and give NE a win in that loss to BUF and arbitrarily say they score 40 in that game.
Brady has played Houston 3 times in New England. All three games NE scored in the 40's. Call that one another game with 40+ points. Over the last few years playing MIA in NE, the Pats have averaged 33 ppg. Brady hasn't played ARI very often, so give the Pats the same output and outcome.
A likely (but certainly impossible to prove) outcome would have been . .
ARI - W (by the same score)
MIA - W (give the Pats another 7 points with Brady in the line up)
HOU - W (give the Pats 14 more points with Brady playing)
BUF - W (let's give NE the 41 they had a few weeks later in BUF)
That's 62 more points than they had without Brady. Add that to the 441 they banked on the season, and the Pats would have 503 points, a 15-1 record, and a scoring differential of 253 points.
Had things played out that way (and they clearly DID NOT), Brady would be looking at around 40 TDs with an equally insane TD to INT ratio and 4700-4800 passing yards. Had things ended up that way (and again, clearly they DID NOT), Brady would have been the MVP going away. People would be saying Ryan had a nice season. Only the cheese heads would be saying look at Rodgers, and there were be very little discussion about who the MVP was this year.
But we are where we are, what happened happened, and what didn't happen didn't happen. The point being, what happened when Brady DIDN'T play should not take away when he DID play.