I still don't think you see what I see. We can go back and forth on this, but I really wanted to know if one transmission would handle both engines, and that was answered. Think I won't bother you guys anymore.
Before I go:
Assume a 134 HP, 88 Ft Lbs straight eight with two power take offs, one between cylinders 2 and 3, and one between cylinders 6 and 7. Power measured at either would be 134 HP and 88 Ft Lbs . . Hook both up to a common drive shaft, and the total power measured at the far end of the drive shaft will be 134 HP and 88 Ft Lbs. Cut that engine in half, connect them together with a Cush coupling, and you have two inline fours, each with 67 HP, and 44 Ft Lbs, but the two outputs connected to a common drive shaft will still total 134 HP and 88 Ft Lbs . The outputs do not fight each other. They add together. Take out the common drive shaft, and join the two outputs through a back driven differential, and the transmissions will split the total power in relation to the ratio of one gear to the other. Put the two transmissions in the same gears, and the split will be 50/50. Put one transmission in the next gear, and the split will asymmetrical, with more power going through one side than the other, but the total power on the differential will add up to the average between what it would be if both transmissions were in the same gear, and if both engines were in the next gear. The differential acts as an averager, not a subtractor. Shifting both transmissions together can be done, ignoring the four in between ratios, but those four would still be available if needed for quicker acceleration, or passing.