Alright, my first (slightly early/unofficial) analysis of Marion:
Would he have been next Scottie Pippen if he had better coaching and a Michael Jordan-type with him on the Phoenix Suns? Hell would I know. He had to fill in for Amare as well.
Based on 2014, he had three things that were the most effective on a coherent team that allowed him to score 10 points and 5 or so rebounds a game:
1. Transition (everything)
2. Pass to cutter/cut and score (vice versa)
3. Shoot from three/fake and drive/plethora of odd shots (Antawn anyone)
Additionally, that capable defense he had is still solid, but age has clearly kicked in. But on a solid 49-win Maverick team that took the Spurs to 7 in the first round, he was between 4th and 7th best guy on the team with those skills alone, behind a selfish Ellis, a 7 foot threat in Dirk (similar to what he had in Amare), an innovator in Calderon (similar to Nash), and in the same range as Vince and Dalembert in importance. There's no question that beating the Spurs would have set off the same magnitude of positioning in the West that happened in 2006 and 2011.
So, based on that, there's a big question mark on Marion. How does he transition from 36 to 37? He is primarily a starter at SF these days, but has proven he can be a sixth man, like he was in 2011. With LeBron taking 36-40 at SF, Marion can provide a role Antawn tried to give in 2010. And I think Marion could do it, behind LBJ and Love, who plays 34-36. In that case, with Tristan and Andy still here, who may be asked to play center a little more than used to, he may get 24 minutes a game at most, even with injuries. It's the least amount throughout his 15 years. And it may work, since he capitalizes on most plays that require possession usage.
Things that would make him effective here:
1. Don't expect 10-5. He needs to play when LeBron sits and when we need defensive stops.
2. If there's half court play, I'd like Love or Andy out there with him for cuts and LeBron/Dion/Irving for passes.
3. We can use him in some Blatt plays, but I'd rather transition and fakes when it comes to dribbling.
Regardless, good signing.