My gut sense it that I'm going to be picking his pieces up if I want him in the girls' lives... My HOPE is that none of that happens.
While it's nice to try to fix things in advance, the fact is you're dealing with a — predictably — unpredictable disordered ex-spouse. He is an adult and you can't live his life for him. Look at the example of divorce court. It doesn't try to change him nor fix him. It deals with "what is", the documented behaviors it sees, and sets an order to outline the boundaries expected of each parent. Likewise, be cautious about "picking his pieces up". You might end up setting yourself an impossible task.