Each owner will draft one player, in a draft randomly determined, who will be their captain. That owner can then only draft players with the same first or last name as the captain, matching first name to first name or last name to last name. For example, Lebron James and James harden could not be teammates.
The captain will be unique to the draft but not to the league. Moses, Karl and Jeff could all be captains and could all have the other two on their teams.
No clones. Cap is 50. No rookies. You can fill your roster with players that cost less than 500k that played with your captain.