But Alonso was a top class footballer until he retired and Nolito was an average player coming on the back of a very good season. Sanchez is more in the Alonso bracket because his game has evolved and he no longer relies on the blistering pace that he had in his younger years.
The biggest strength of Sanchez's game is his ability to keep the ball and his intelligence. He still has that ability to beat defenders with a sharp turn or his control and it was evident at the Etihad this year on a number of occasions. That skill set is going to be crucial in the CL because Sane and even Kun these days, fail to keep the ball under pressure. Sanchez is not going to lose those abilities over the next 2 and a half seasons.
Furthermore, there is also the mentality that he has. He's a born winner and has dragged Arsenal to trophies over recent seasons and there is no doubt in my mind that his presence would ensure that Sane and Jesus would not be allowed to rest of their laurels.
You have to strike whilst the iron is hot in football and Sanchez would easily improve our team. Whether that is for two years only then so be it because we have the chance now, with Pep in charge to dominate the PL. Players like Sanchez who would cost less than Lingard in today's market would give us the better chance of doing so.