if built by the same builder , the 3x (both sides) should* be stronger but the driveside of the rear wheel will be under the most torque (obviously) which is why 3x needs to be there. you can save grams by building in radial, but lets not get into the argument on weight of radial vs 3x.... the fact is, it will weight less. and for normal road and race applications (track too) radial nondriveside will survive.

many road wheel manufacturers although using different hubs/spokes also employ radial nondriveside