The work that Greg Kirkpatrick did on Marathon and Marathon 2 earned Bungie a shitload of credit from their fans, enough that they could have produced more than a decade's worth of horseshit storylines and no one would have really cared as long as the underlying gameplay was good and the multiplayer was kickass. Such an environment can be challenging for a story lead, but not in the ways that will make him a better story lead.
This new gig sounds like it's going to be challenging for him, but in all the right ways. Within a few years I'll be very interested to see what sort of work Joe Staten is doing.