It's not. There are 2 weight divisions between them. Even more because Rigo isn't even big at 122. The fight would have been great 1-2 years ago when Loma was fighting at 126. Rigo didn't accept the fight at that weight back then. Now if Loma beats Rigo at 130 he will get no credit for that, just like GGG got no credit for beating Brook.
These guys are probably the most skilled boxers in boxing. I agree that Loma will be favored and likely to win as it will be a case of a great big man beating a great small man, but still, Rigo is a live dog and the fight could be a lot closer than people think.
McGregor is just another guy with diarrhoea of the mouth. There are far more people imploring Rigo to man up and fight Loma: the sensible people here know what time it is.