The staff wants additional '18 guys. They've offered guys like Luis Rodriguez, Tevian Jones, Maurice Calloo (a couple others?) since missing out on targets this fall.
There are currently 5 spots open for '19, so you can take two more players in '18 (which I would guess they'll do) and still add the three targets you mention in '19.
As for the attractiveness to bigs, it depends on the big. This system isn't for back-to-the-basket traditional bigs (think Isaac Haas), but it's great for guys with some face-up game and ability to run the floor.
Really hoping Flo Thamba takes a visit here