Who do you build a team around? Who's the keystone, the most important player? On offense, is it the QB? The RB? or neither. Do you actually build it around the O-Line and then fill-in.
Maybe you build your team around the defense first. If so, who's the most important guy to him. A great middle linebacker? A pass rushing DE? A shutdown cb? A ball hawking safety?
I grew up believing that on offense you start with a great O-line. A great O-line makes the rbs better and makes a decent QB ala Mark Rypien a probowler and MVP. I don't think it's qb, because I look at the Marino's, the Elway's and while they elevated their team, until they got the compliment they couldn't reach the goal. Elway needed his rb. Marino never got there.
On D, I'm less sure. You need a great general. Someone on the field that can get in everyone's ear, make the play, and make sure everyone knows what's going on. I think my order of importance would go middle linebacker, followed by a d line, corners, outside linebackers with safeties last.