Monzon would've been taller than Hopkins, Monzon also had a granite like chin and Hopkins would not knock him out. Monzon had a huge right hand, thus the nickname 'shotgun' ! Monzon wins everytime, because he would just find a way.

“Monzón is the complete fighter. He can box, he can hit, he can think, and he is game all the way."~Angelo Dundee

Monzon is without doubt one of the 3 best Middleweights of all time, he drank, he smoked cigars, he fucked anything that moved, got shot by one of his wives, beat up on paparazzi and only began training one month before any scheduled world title fight.

While still a champion, a darker side of Monzón would begin to emerge. In 1973, Monzón was shot in the leg by his wife, requiring 7 hours of surgery to remove the bullet. In 1975, he began a very publicized romance with the famous actress and vedette Susana Giménez; they had previously met in the 1974 thriller La Mary, directed by Daniel Tinayre, where the two played husband and wife. Monzón hated paparazzi who detailed his affairs. He went to Italy with Giménez to participate in a movie and started increasingly traveling with her to locations in Brazil and the rest of Latin America, letting himself be seen with her, though still married. He was accused of domestic violence and of beating paparazzi. The fascination of the media with Monzón's private life reached its highest point with his trial for the murder of his concubine and his death in a car crash soon thereafter.
Can you imagine what this guy would've have accomplished had he really tried?
Monzon was a sinister character and not that well known in the USA, but in the ring he was a beast, a fighter who was the best in the world at the time fighting at approximately 75-80% of his best due to an out of control lifestyle.
There is a movie to be made here and what a story it is.