I agree that there's a big difference between tough and petulantly dirty. I hope we don't go down that road as it serves no one.We both know there's a world of difference between what Spurs and PSG did to being tough/hard to play against. It was the fact his teams did it twice which tells me it wasn't the players losing their heads, it was him telling them to lose their heads.
I've said elsewhere I think next year will probably be the most difficult PL season of all time. City look superb, Liverpool are finding form and a team, Newcastle have done well, United will have to strengthen, Arsenal will still be decent. Chelsea have some great players but something just doesn't seem right (to me, as an outsider). I think Pochettino will get you playing decent football and I think he will get a lot more out of that squad than recent managers have but I think he's a short term solution (then again, have you ever had a long term one? :) )
By rights, a XI with Mendy, James, Thiago, Koulibaly, Chilwell, Fernandez, Kante, Kovacic, Joao Felix, Sterling and Aubameyang should be very close to the top and no where near the likes of Brentford etc.
All I'm saying is that we do certainly need some steel, so it's a risk we have to take at this point, I think.
I also agree that Poch is probably a short term fix.