I think people are seeing things in Tolisso that aren't really there. They are hoping he is some Pogba/Vidal hybrid or something. Some type of B2B engine like we had in the old days.
I think he's a fine player but he's not a catalyst type. He's not Nainggolan or something like that. He's not a CAM, that's for sure. And is it wise to spend 40M on a 2 man DM? I don't think so personally.
If you can get Bernardeschi for the same price, I'd rather do that.