AnFI, i get your last statement....but I think in the middle ground you get really cloudy on the comparison. Im not sure if you're over thinking it or what.
More parts equals more possible problems, but when engineered to spread the loading, than more parts equals more reliability.
I'm not going to try and compare anything inside the gearbox to try and convince you, i'm simply going to use rope as an example and perhaps that simple comparison will suffice.
How strong is rope when there is 1 strand, versus rope with multiple strands?