While Strome certainly has potential, I'd prefer to get a centre with at least a little NHL experience. It'd be too risky putting him in the top line and relying on him to play top minutes when he's only played in the OHL.
I'd be willing to part with Kessel to get a #1 center as our #5 pick seems like it will be Forsberg, a winger who can possibly replace Kessel in a couple years. Also I think #1 centers are very valuable and are almost never an overpayment when trading for one since they are just that rare. In my opinion one of Kessel or 5th overall is available, but not both.
Gardiner you can make the case for, but Strome definitely holds more value than Kadri.
Please explain how a prospect still in junior who hasn't shown significant improvement from his draft year is more valuable than a prospect who has done very well in the AHL and has shown he can play well at times in the NHL. There is a better than 75% chance that Kadri will play a full NHL season next year and we don't even know if Strome can compete at the AHL level. Is it because Kadri is a Leafs prospect and Strome isn't?
J Schultz > Gardiner (according to the coach of both)
J Schultz was said to go 5-10th in this draft...ergo...
Probably true since it's rumoured (or outright told, not sure) the leafs asked to get Schultz in that trade instead of Gardiner. However, Gardiner has made the jump to the NHL and played well so at least for now I would have to say Gardiner > Schultz although that can easily change after we see Schultz for a couple dozen NHL games.