At the risk of being catastrophic, how about the staff wages being like the players ones? (fixed weekly, rising in the offseason).
I suppose it would impact the staff market greatly (which currently seems like a huge economy drain, rightfully or not) but the "gains" and even the potential "savings" on eventually not having to constantly hire new staff could be funneled towards the superstar players/overall roster, maybe? I'm probably not having a full view of the effects but feel free to let me know
Also, if you want to add some strategy or what not to it, maybe the coaches could have a stronger (and likewise weaker) offensive/defensive strategy, if it makes sense of course.