I don't think Eli manning can carry a team like brees can, or Big Ben for that matter. They've led their teams to multiple Super Bowls.
The Steelers made and won Super Bowl XL because of their top 3 defense and stud running attack. Hell Big Ben only started 12 games that season and they had the fewest passing attempts in the league that year. In 2008, they had the best defense in the league and Big Ben had 17 tds to 15 picks and a 80.5 QB rating. Big Ben was more than a game manager, but not much more. It's no coincidence that the more that offense and that team depends on Big Ben, the less successful they are.
As for Eli, he's very inconsistent. He doesn't have a great completion percentage, he throws a lot of picks, and he doesn't have the best arm. I'll give credit for last season - even though he had 2 receivers who were in the top 25 in the league - but he's not better than Joe.
Brees has never carried a team either. He was a failure in San Diego, but mix him up with a top 3 playcaller in the NFL and a stud offensive supporting cast and anyone will throw up beast numbers (including in the turnover department).