The methodology for the assessment of the field is not very robust at all. It assumes that they top two in each region will get the auto slots and does not look in to the alternative possibilities. Look at the Great Lakes Regional. It assumes that currently #12 Michigan beats currently #20 Indiana. However, since Michigan has lots of points and will get in if they are three or four (or five?), they are more likely to go a bit easier in the Regional race than #27 Michigan State or #20 Indiana. Look at what Drenth has done with the women and why would we be surprised if the men showed up well with good hard training and with a top leader at the front. Similarly, Indiana has shown up repeatedly when it comes to crunch time (e.g., last year, even when they lost their best runner and finished eighth). If Indiana gets in, a whole cascade of differences enters into the calculus because then a lot of teams get points (in addition to the Michigan squad that does not finished top two.
Going further on that score, I think that Michigan might go to finish first in the Regional but if that does not look like it is going to happen, then dropping off and saving themselves for NCAAs makes sense. And if Michigan loses to MSU and IU, then those teams both get more points, one of them is in and then more points fall.
I think that a few of these not too unlikely scenarios ought to be looked at.