Here is the main difference in outboard rigging. Inland and offshore. That's is the main thing that will determine if a boat builder goes one way or the other. And I agree with you in our region (Minnesota). We see nothing but single outboards all the way up into the 400 class on fishing boats and pontoons. (minus the 9.9hp kicker motors) That being said, the only ones going with more than one, are looking for more than what a single outboard can put out. But it's rare.
Now the opposite is true for offshore boats. If you spend any time on Youtube channels like Wavy Boats etc, you will hardly ever see an offshore designed boat with a single engine or single outboard. And it's not just lack of HP, it is for the fault tolerance reason of multiple motors. The very few with single outboards are usually tender boats, or inland boats that someone took offshore.
(and yes, I am addicted to boat watching youtube channels. I can't get enough of the big Midnight Express boats with 5-450R motors)
I’m with you on youtube watching … those big Midnight express and others just own haul over even on rougher days with the right person at the helm.
So those lake boats with the kickers, they not only have those for trolling, but that also gives them some
motive power in the event that the big boy motor decides
to go on strike (50 points if you can get my reference there). A friend of mine on the west coast takes his pilot house Parker wayyyyyy off shore with the single 200 Yamaha motor. One time they were wayyy out there and the fuel pump said no more and they had to get a tow back in. Personally I think he’s a bit crazy going with the single engine, but he is prepared for such an occurrence. One of the things I wanted in a boat was twin engines for reliability, to me its kinda like getting a truck with four wheel drive, the first time you get stuck and you just twist a knob and drive away it is worth every penning of the $4K or so you paid for It. I do not want to be at the mercy of others if an ignition box decides its done with life, especially when no one else is around.
Also, I have plans to tackle some of the bigger lakes in the Dakota’s and MT, Ohae for example is 261 miles long and connects the state capitals of North and South Dakota. I think there is maybe three, more likely two places to get fuel on the water on Lake Oahe, one for sure is just south of Mobridge, the other is 150 miles away in Bismarck. So, two engines is greatly desired. I have seen several other boats over on the east side that are running twins, which is where I usually see the only other CC boats, although my one neighbor has two Boston Whalers, a DC and a CC, both have twin outboards on them. He obviously is making some good money, but he also has little time to use either boat. Keeping the big water in mind of the big lakes, I’m engaged in a frequent mental karate match about upgrading to the 252 FSH with its taller free board and more offshore orientated hull.