Administrative (non-assistant positions) can be as many as you want and you can call them anything you want.
One position that is used prominently is DOBO, but that is not a requirement. You can call it something else, or you can have 5 people doing that job. Remember the NCAA doesn't regulate how many people can be on your total staff, what they regulate are recruiting assistants.
They also regulate who can work with players on the court. But you're right, you can have as many people as you want on a "staff". You can call them "video coordinators","assistant video coordinators" , "travel coordinators" etc..
The only thing I would worry about here is "to many cooks spoiling the broth". You bring in Pinckney and Richmond and you have all these basketball people on the staff; it's going to be like the Tower of Babble. And Matt is an important assistant and he is going to be relegated to sitting off to the side, listening to all these NBA guys argue over what they are going to be doing. That's my worry.
This was the whole reason why the NCAA came up with the 2 year rule where a player cannot play for a team if a coach on that staff was associated within the last 2 years with that player UNLESS that coach is one of the 3 MAIN assistant coaches.
Because Bill Self would hire Mario Chalmers father in an administrative position and then land his son. Bill Self could create 10K administrative positions if he wanted to just to land a player. The NCAA rule is used to prevent this from happening.
But since you only get 3 assistants you better be careful who you hire just to get a player. See Seton Hall hiring Tiny Morton. In the old rules Willard or even Lavin could have hired Morton in an administrative role and still get Whitehead. But not anymore. Tiny needed to be hired as one of the 3 main assistants or it doesn’t work.
It is also why SJU could not get Lamont Jones as a transfer in 2011, remember? Because Mo Hicks was DOBO and he within the previous 2 years had an AAU association with Jones. Since Mo Hicks was NOT one of the 3 main assistants SJU could not recruit him and thus he transferred to Iona from Arizona when we know his first choice was SJU.