Colby, as you know I have not run a marathon before... and the only one I'm doing is at the end of an Ironman... BBBUUUUTTTT... I think you need to look at what you did last year and the results that training produced.

Honestly, that marathon training plan looks very odd. But for some people, the cross training might do them good. I know for me, I can't run everyday so it would work for me. Now, how fast would my marathon be... who knows?