Uhmm, I think you are just a very avid fan of the Pacman that you bet on him without first examining the opponent and this time you will lost your bet but fortunately for you mate, this fight is not gonna happen. In the first place, team Pacman is not considering this fight, it's only Roach who spread this rumor and he ain't the trainer of Manny anymore, he will be in Manny's corner as a consultant AFAIK.
Manny have the luxury of cherry picking his next opponent and it would be between the two Garcia's (Danny and Mikey) if he can't get that rematch with Floyd Mayweather.
Reading your post, yeah I guess you could say I am an avid fan of him. Been betting to him since he's putting a show on every flashy ring he went up to, either Las Vegas or in other places. Though it is not that I am underestimating his enemy. Triple G is a great boxer, I just remembered how people debate like this when Manny fought against Margarito which is also a great boxer with a great advantage in height against Manny. I just thought that it would be the same.
Age is great factor and do really affect everything from speed to reflexes to stamina etc. We can see the difference in age but not really that much since Golovkin is already 38 years old as i remember.
I dont know why people do presume out Margarito with GGG as we can see the difference between fighters and i can say that ggg is way more dangerous and much better.
I still doubt the winning chance of Pacquio on here even if he do have the speed but it would really be enough to take him down? It would be hard.