I knew Trumpets back in the day. Do they still have all their cylinders sending the pistons in the same direction at the same time? Seemed silly then, still does. :{)
Odd, we used to spend a good bit of money on having a good-quality machine shop split the crankshaft of a high-performance two-cycle and have it reworked into that *parallel twin* configuration. A *TWINgle it was called back in the day, with torque, torque, and more torque in the lower end of the power curve. There was an Irish lad named Sammy Miller who did pretty well on such bikes.