Saying the Hansons jumped the shark is silly. Given all the variables, on the men's side they did as well as any comparable training group, and better than any other on the women's side.
And by comparable training group, I mean a group that isn't made up of runners with individual shoe contracts. Comparing Schumacher's, Salazar's, or McMahon's groups made up of runners with individual shoe contracts is not a fair comparison, because those groups are starting out with the top talent coming out of college, where the Hansons, McMillan, Zap, etc. are not. In fact, that's the whole point of a group like the Hansons or McMillan - to give that next tier of runners a chance to improve and have professional careers.
If it now takes sub 2:10 to get on the team, however, there are not many people out there with that potential, and many of them are going to get big shoe contracts rather go with the Hansons, McMillan, etc., so it may be harder for groups like the Hansons to place runners in the top 3 in the future.