New bearings, difficult to rotate the crankshaft.

One problem with the one by one method.... If you have the rod caps switched around,,, what rods are wrong as a combination??? In other words, if one is bad, then at least two are bad.... Make sence???
The only way to confirm your rods are assembled correctly would be to mic them when torgued with a telescopic gauge or take them to a machine shop and they can check them for out of round.
If you have the patience, you can "as I do" place a bearing into each rod and main journal, measure the inside diameter, then measure the journals of the crank. You can play around with swapping bearings back and forth between caps and saddles untill you get the most common clearance between the bearings and there respective journals.
Might seem like over-kill, but I have the warm and fuzzy feeling when I'm done with my build!