Kaspar took a lowly, losing program at SFA and built it into a regular 20-game winner. (He won 21 games in his third and fourth year, then had a down stretch for the next three years before bouncing back and becoming a regular winner.) Underwood has kept the momentum going and won with a mix of Kaspar's players (he recruited last two SLC players of year) and his own.
Kaspar is in his third year rebuilding a struggling Texas State program that lacked the discipline and talent to win in D1. He also turned Incarnate Word into a lower-level winner before going to SFA, so I'd be surprised if he's unable to win at Texas State.