That's almost always correct. The operative word here is "almost". Case in point:

I have a '93 Trek 7000 MTB (bonded Al frame, rigid fork, hardtail, LX components, 68 mm bb shell.) that came with a Tange cup-and-cone bb with a 133 mm unsymmetrical bolted spindle.

The first time I overhauled it, I discovered the spindle had been installed "backwards" (long end to the nds) at the factory. I mumbled something about those incompetents in Wisconsin and proceeded to install it "correctly". Then I installed the crank arms only to find the nds crank arm hit the chainstay!

Apparently the stays are so fat a regular spindle wasn't long enough to clear them so Trek used a very long spindle and put the long end to the nds. The "short" end of the spindle was long enough so the chainrings and the crank arm cleared the chainstays on the drive side.

I eventually replaced the Tange with a Shimano cartridge bb but had to use a 127.5 mm spindle (the longest I could find) and the nds crank just misses the chainstay by about 4 mm.