Not exactly sure what you're describing...
I clip the spring onto the driveshaft, put the pinion end of the driveshaft into
the pinion cup, and slide the whole thing, final drive and all, into place.
It is often hard or frustrating trying to get the drive shaft to mate with the
universal joint, but once it "goes in" it is in, it can't go almost in or anything
like that.
LIfting the swingarm to level or even beyond level helps with the
mating of the drive shaft and the universal...
Have I missed your point entirely?

-Mike