Wow... Djokovic 2.0 couldn't beat Olderer RG 2011 and yet you think he would beat Primerer?
That's why it is an unpopular opinion
I think Federer played one of his very best matches that day and one of his best ever French Opens, consistently better than when he won in 2009 for example.
I also think that whilst Djokovic had a fantastic clay-court season, he has had several better individual matches.
Djokovic hadn't played for five days and seemed to be caught a little cold early in that match, I think he has played better matches in subsequent French Opens than on that day but that's just my opinion.
Out of interest, would you be more open to me saying peak Djokovic is better than peak Federer on clay but wouldn't necessarily beat him? I'm not sure if I think that's true but you could make an argument for it based on his record against Nadal. (I'm not forgetting Federer's achievements on clay but I don't want the post to be too long).