I wonder how these collectives actually operate. Are they mostly there as support organizations to help a student-athlete financially once they're signed and on campus? Or are they going out there recruiting? And if they're going out recruiting, are they recruiting specific players at the behest of the coaching staffs (who identify and prioritize target players)? Or are they going out and just independently trying to work with recruits that have offers/etc?
I realize all that they really need is to make any of this stuff an arms-length transaction. But I wonder how much coordination is behind these guys...
Officially-- no interaction.

Unofficially-- Yeah, it's all just a bunch of smoke and mirrors to produce the illusion of an arms-length transaction.
Here's how I hear it probably, usually goes down, at least at the places that are at least TRYING to keep a facade of propriety. Coaches go and recruit a kid. They tell the kid, "look, from what I hear, recruits with your * ranking at your position, are typically getting $X per year." Meanwhile they're confirming with the collective that once the recruit is on campus, that will indeed be the likely amount of money paid for the recruit's NIL.
These collectives aren't dumb, the deals are typically tied to required activities (be in this ad, or show up for this charity event, etc.) and they aren't ever-green, they're usually just for a year at a time. So if a kid portals out after one year, he doesn't take 4 years worth of NIL money along with him.
Those are the specifics for the how the collectives tend to work, that is.
The REAL NIL deals are set up directly between Company Y and Recruit B, based entirely on perceived marketing benefit. Things like Caleb Williams in the Dr. Pepper commercials, Quinn Ewers advocating a specific packaged tea brand, etc. Those kids made those deals independently and would presumably retain them no matter where they went, unless of course, say, Ewers decided to transfer from Texas, to North Dakota State, where his expected marketing value would necessarily decrease, and the tea company could either cut him, or pay him less.