Baby's biggest problem, which has already been well versed here, is that he wants to shoot too much. When he is getting his shots and playing what he feels is an active role in an offense, he hustles, takes charges, sets strong screens, and can energize a team with his play.
OKC is a team that could really use a player that is willing to take and can make some shots. When they have Sefalosha and Perk on the floor together, they need a 3rd player who is willing to take shots and Baby is that kind of player. OKC is also a young team that is slowly gathering playoff experience and you could see what kind of impact acquiring Perk and his playoff experience brought to the team. Bringing in Baby wouldn't amplify that much more, but perhaps a little bit.
I think OKC would be wise to offer Baby something like 3 years, 9 mil with a team option on the 3rd year.