I don't think that's a fair assumption. Completely different conditions now. It depends how good he actually was, and how much he could have improved from that level to be able to be considered one of the best in the current era. Loads of players seem to have huge potential when they are young...
He might be, or he might not. We haven't seen him against the current standard. Even if you upgrade what was available to him to the current level, we don't know how he'd fare against the current level.
This is the impression I get from watching games from before my time. Some of the defending is hilarious. Football seems to have moved on and become far more professional. From what I gather, a lot more time is now put into preparation, tactics, fitness, diet as well as a general lift in overall...