Ritz' best fall seasons were after full track summers (2009/2012). Had he run a marathon rather than his 60flat in 09, he probably would have run 2:06 that fall.
The single best thing to happen to Dathan was not making the Olympic team in the marathon. He was able to work on his speed a bit last spring/summer in anticipation for the 10,000, he was able to experience the Olympics, he still got paid for a fall marathon... where he PRd, and it set him up well for a return to the track this year.
Ritz would do well, and would probably last longer, if he ran 1 fall marathon, cross, summer track through 2016... exactly this year/2009s schedule and similar to last year's.
If he stayed healthy and followed that schedule, I see Ritz under 13:00 and probably at high 26:40s, low 26:50s at some point in the next 3 years before topping out and starting to slow down.
He would comfortably make mid 6 figures on this schedule, and after Rio, he could dedicate himself to the marathon for the next cycle.