RE: twin terror
That is a very good question. I guess assuming a 2cylinder in-line and this v-config with a coupling crankshaft, the in-line 2cylinder has the benefit of one less moving part (their cranks are coupled together directly in line, no gears for that) and thus also less friction from gear teeth mesh interface because that is one less gear that has to be turned. Also, the inline 2 cylinder would be lighter and smaller, so it can fit into a shallower hull will keeping the center of mass low and closer to the waterline.