The problem with Newton is that nobody knows whether he can play or at what level. The problem with all of those guys in general is that they haven’t played in a system similar to Nagy’s before, and bringing someone like that in for a “make or break” year is not likely to turn out well in the short term. Pace and Nagy aren’t looking long term at this point, because the long term won’t include them if the short term doesn’t work out.
Foles has played extremely well in a system similar to Nagy’s before, making him the best chance for improving the team THIS year.