How I would work it is like the NFL.
You have us the owners who pick our own HC, how they are allocated is by a draw or raffle if you like, so it will be down to luck. Just like the draft you can put in your 1st, 2nd 3rd etc... choices.
Then, and this is where it gets interesting, there will be OCs and DCs that favor some HCs over others, character, schemes, old friendships and opportunities. This could then filter down the rest of the CS.
I'm not sure if this could be done, but its how I would like to see it done if this happens.