First, you have to understand that Herman is considered incredibly bright and has a great reputation in coaching circles. There is a reason he basically gets linked to every high profile job opening.
Second, he definitely leveraged his deep connections to Texas. This is a guy who started his coaching career as a GA under Mack Brown at Texas then worked his way up through the coaching ranks in the state and really got his big break at Rice, so he is well regarded in Houston.
So once he got hired, he quickly hired some assistants from local high schools and assistants like Major Applewhite, Oscar Giles, and Darrell Wyatt who all have deep Texas ties (especially to Mack Brown). I doubt the budget for the assistant pool is very big, but he seems to have found a mix of local coaches moving up and former P5 assistants rehabilitating their image. His coaching staff is full of guys who know Texas (and especially Houston) recruiting quite intimately. No substitute for strong ties.
The fact he cleverly adapted the #HTownTakeover on Twitter was probably icing on the cake.