Coaches ratings can move up or down just like players. You'll want to hire young coaches who increase by at least an average of 2 points per season. In the grand scheme of things position coaches are probably the least important in contributing to MFN success.

I've never paid attention to this until recently when hiring unemployed coaches I've aimed to go with the younger ones but I've never tracked the movement of coaches' ratings.

Greg is absolutely right. Beyond making sure I get the best ratings possible on the first three coaches (HC/OFF/DEF coordinators) I pay 0% attention to this aspect.

Perhaps there's an angle/edge to be gained here, though.

HCs carry the playbooks so learning which ones contain which plays is vital but tbh I've always just taken the hand I was dealt.