There is only one true narrative - the coaches BEGGED Taysom to return, including a call very early on from new coach Sitake, and when he decided to return, how were they going to make him ride the bench the whole season? Frankly those early conversations probably included a guarantee to start. Tanner had 3 years of eligibility, so they made the obvious choice. If they had each had one year left of eligibility, there would've been a different conversation.
Based on what we've seen, the offense is not too complicated. Tanner will do great.