Stamas had a V-21 in 1974?

[willy]

When my wife and I were in Puerto Rico in December I saw several interesting boats, including a few that looked just like that Stamas above, and a few Mako's too, what made them interesting to me at least was the fact that they were all running two motors, two smaller motors like two 50's or two 75's etc. just like the Stamas in the photo above. When I talked with the local fellow there about the fishing I asked him about the motor set up and he acted like why would you set up a boat any other way. He said that they are fishing by themselves a lot and they have a lot of reefs and rocks they move around inshore and can't be out there with just one engine, too dangerous.
I wonder, if you had two 75's that would have to perform better than a single 150 right? I mean you have two props biting in the water , like extra torque being applied to the pushing of the hull right?