Not sure Tosin is ready, and what worries me is he lacks the actual footballing ability. Denayer and Mangala aren't good enough, so not signing Stones would be a huge disappointment for me.
"Actual footballing ability"
What does that even mean? It's a complete nothing of a phrase.
Tosin has always been praised for his ability and skill on the ball, if that's what you're alluding to, so you're simply wrong there. If he has a problem it seems to be concentration - pretty common for young CB's.