You need to educate yourself.
I dont agree that a H2H match up between two guys in different weightclasses would settle any discussion but if you are "extremely confident" of it, then there should be no doubts in this discussion for you:
1- Odds favoured Silva in that fight.
2- GSP refused to take on the challenge, according to the promoter himself, despite it would get him more money and legacy. It seems GSP didnt liked his chances.
i highly doubt, extremely highly doubt that given equal body fat percentages that Silva was more than 10 pounds heavier than GSP, I'm guessing it would be closer to 5 pounds.
Silva noticeably had a higher body fat % and even with it I doubt he weighed more than 10 pounds more on fight night.
The gsp fight with Silva was the fight to make. It made sense and it would have been billed as and even without the billing been seen as the fight to decide the p4p goat.
Sometimes that sort of situation arises in the case of GSP and Silva, at that time in that era, it was the case.
Without that fight happening there isn't a GOAT that's just how it goes.
Before you make the arguement of GOAT from different eras disproves there's a goat. That's a different discussion. Just like if GSP would have beaten Anderson Silva is a different discussion. What I'm talking about are the fights to make within a fighters career to earn that title, not just the fights themselves but the attitude and surrounding behavior. That's what's been watered down and lost over time.
If you want to just make more excuses, or arguments as you see them to prove me wrong then, in my eyes your just working to prove me right. That's when, imo, it started to get watered down. You, see this argument is a kind of time capsule from that time and by that time 'It' had already been watered down. People replaced the idea of greatness with arguing against it's existence. To quote Dana White, "It's sad."