Like hell you can't make that statement, yet.

The 1st gen Xterra used a R200 front differential, and axle shafts to fit. The 2nd gen uses a R180 high pinion front axle, and axle shafts to match. The R180 IS a significantly weaker axle, however, the high pinion version should make the gears, at least, be about equivalent.

But you're going to find it pretty obvious that the 2nd gen actual axle shafts are R180 axle shafts, and yes, they ARE weaker.

Not to mention, there's a buttload more torque coming from the 2nd gen's engine & t-case combo, over the 1st gen.

In other words, find a source of used axle shafts. You're going to need them if you wheel ANY IFS rig. Including the 2nd gen Xterra.