Ryan needs an experienced play caller and someone who knows how to establish the run. And an adult in the booth to suggest varying the snap count. This hire should help nicely in those areas.
No one thought that was Brian, but the alternative was to lose the best wr recruiter in the history of the game, so he was promoted with those limitations.
Ryan does not need any help with passing schemes, other than possibly getting back to a wr rotation and perimeter blocking. Versus indiana and Miami, they schemed wrs open plenty often, the young QB simply was fleeing too often (in reality or out of fear of what had just happened).
Brian had his flaws, but overall still unleashed an absurdly talented pair of WRs, with KDW, Henry and Guilford coming in, and brown up next. His inevitable departure only cost them a few backups and a west Coast wr always flirting with usc.
In the end, it was likely the ol recruiting/development that was the true achilles heel. Whatever the schematic flaws, or Julian's youth, or the depth issues at wr, they narrowly lost to the two championship game participants. It almost worked.
P.s. if we are fixating on single seasons, steer clear of chip in San fran.