[shinsengumi]

The question, I suppose, is whether this was a temporary dry period, where a bunch of guys (Wilkerson, Young, Wright, Seale, Sanders) have either been bad fits for our offense or just recruiting misses and it has just been bad luck, or whether something has changed such that the type of running back we are looking for is just not available to us any more.

I think you are avoiding a plausible explanation - lack of player development.

[shinsengumi]

The question, I suppose, is whether this was a temporary dry period, where a bunch of guys (Wilkerson, Young, Wright, Seale, Sanders) have either been bad fits for our offense or just recruiting misses and it has just been bad luck, or whether something has changed such that the type of running back we are looking for is just not available to us any more.

I think you are avoiding a plausible explanation - lack of player development.