I'm going to let them organize themselves. One prominent firm in this area does a reshuffle of their managers each year. The president assigns the manager to a particular division. Then managers go out and pick their teams from existing employees. Offers are made.
Bidding wars occur for talent.
Some employees solicit spots on a particular manager's team. In the end it seems to work. People end up working with those they are interested in working with. I don't think I can really pick a group of team leaders. So I'm leaning toward just letting it sort itself out.