Looking back at the squads like that is not accurate though. At different times, different players were at their peak/poor/injured etc. And some teams just weren't teams, they were collections of players.
Reminds me of people looking back at AC Milan midfield in 00s and wondering how did they win so few league titles. On paper, Seedorf, Pirlo, Gattuso and Kaka etc. look great. Yet, Barca with Edmilson, Van Bommel, Iniesta and Ronaldinho completely dominated that midfield in their home turf.
http://www.uefa.com/uefachampionsleague/season=2005/matches/round=2204/match=1107456/postmatch/lineups/index.html
I agree that taking a squad in isolation only gives you a snapshot. As does comparing how 2 teams midfield compared in a single game
I suppose the over arching point is that Maradona played in a competition that was much, much stronger in depth than what Messi and Ronaldo have to face now. Serie A was the league that could attract virtually all the top stars. It was the best league with the most money. Not just 2 or 3 teams either. We are talking 7 or 8 teams who had a load of top stars playing for them.
The late 80's and early 90's was also a time when there was a greater spread of top talent. Every top team in Europe had 14/15 international rather than 25. You had a situation where there was a concentration of the absolute top talent within a single league but that top talent was then spread across the league. Teams like Sampdoria had truly top players playing for them even though they weren't a big club in Italy. Look at the early to mid 90's Parma team that never won a Serie A title. Some absolutely outstanding players.
Football since the mid 2000's has not been like that. The good thing is that the top players seem to be spread more evenly across 4 or 5 leagues. I believe there is genuinely World Class players playing in every one of the top 5 leagues. The issue is that talent is concentrated within a couple of teams within each league. That make the depth of each domestic competition quite poor.
That's the main reason why i find it hard to rate Messi or C.Ronaldo against Maradona. At a push I'd probably say Messi edges out C.Ronaldo. It's a wafer thin difference though. Is Maradona better than Messi or C.Ronaldo? Maybe not. But he's better than any other player thats played in that period between the mid 80's and now.
This would be the best team I've seen since watching football:
Buffon
Thruam Desially Baresi Maldini
Xavi Matthäus Zidane
C.Ronaldo Maradona Messi
Subs: Schmeichel, Cafu, Cannavaro, Iniesta, Ronaldinho, van Basten, Ronaldo
The front 3 plus Maldini, Zidane and Matthäus are absolute shoe-ins. On another day I could easily change the other 5 players. Same with the bench. Really wanted to find a place for Batistuta but he's not as good as Ronaldo or van Basten!