If we'd got him when Arsenal did we'd have won more than just a league cup in the last three seasons.
Not sure about now because he's 29 this year and we need to get the average age down. It's fitting him into the side as well with Serg and Jesus.
Age really doesn't really matter with Sanchez IMO.
We have Sané 21, Jesus 20 and Sterling 22. Behind them there's Sancho and Diaz at 18/19 and Roberts & Moreno on loan. We have young wingers coming out of our ears.
Sanchez would be coming in for 2 or 3 years just to deliver instant success, and raise the level of the squad. Be the best team in the country, and one of the best in Europe immediately, not waiting for the 3 kids to iron out the cracks in their game before we win things, let them do it whilst the squad is successful.
Playing with someone like him, and also winning loads will be a great influence on the younger players and when Sanchez left in say 2020, we wont be in a position where there's no one to replace him - in fact I imagine they'll have pushed him to the bench by the time he leaves.
But we do need some success immediately, to get the project going, to make the players believe they're world beaters.
The game time needs to be carefully managed but I doubt Pep would be going for him if he wasn't sure it was possible.