The situation with Tek, Roony and Martin is a bit easier than the rest.
Martin is already registered as B team player, he just can't play more than 10 game, Tek is Free Agent, so he can be registered any time, Roony can be registered as B team player, at least until we give him minutes, I doubt the BS about La Liga forbidden it is true, and even if true, it can be delayed in September.
So, while it will be pain in the ass for Flick, the club really doesn't risk losing those players for free, like we had with Olmo and other players before.
The club will likely register Tek first, once Pena leaves, then gives it a try for the rest. Personal guarantees might be used with the ideal that we will return to Camp Nou and VIP will be validated