First, Sancho and Jeffrey did not quit North East Stars. But they are no longer with the club. I would expect some kind of statement soon.
The problem with Roopie is that it was revealed in an article that he played for two clubs in USA. The ProLeague saw this article (and placed it on their website) and quite rightfully informed North East that he would require transfer papers from the previous club. (This is a FIFA ruling, not a Pro League rule)
Roopie says that although he played some games, he had no contract and did not register. This needs to be examined because in most leagues clubs are fined for playing unregistered players.
This may seem very frustrating, but there is a process and its for perfectly good reasons and relates back to the Bosman Ruling concerning freedom of movement. There are also rules concerning the number of clubs you register for in one season. You may recall that Mascherano had a problem when he played for West Ham and went on loan to Liverpool. I can't remember all of the details, but I think he was supposed to sign for another club, but if he did this, he wouldn't be eligible to play. Maybe someone can refresh my memory?
Point is, there must be correct documentation and a clear paper trail when signing players. In this instance, don't blame Dexter Skeene or the Pro League.