If all Chess World Champions were simultaneously alive?

Newcomers to Chess will find this helpful.

I'm really not sure that Alekhine should be at or near the top. Alekhine was supposed to be weaker than Capablanca; his superior preparation (and to be fair, Capa's laziness) led to Alekhine winning, but Alekhine evaded a re-match, where possibly the greatest natural player ever would surely have prepared more.

With regards to the hypothetical scenario, it would need to be during or after Carlsen's reign. All other players appear and get to study the games of what to them are future players for an agreed period - a year, perhaps - including the chance to play in practice tournaments.

I wish Tony miles were alive, took a pawn and said "this is ding" and begann steering his Coffee with it