No Laser Guide Stars for adaptive optics in giant telescopes?

In order to get diffraction limited imaging on large telescopes using Laser Guide Stars one needs to fire several such artificial beacons angularly displaced with respect to the science target. Such displacement scales with the diameter of the telescope. It is pointed out that when this angle exceeds some given figure it can be more efficient to use directly some off–axis Natural Guide Stars. With realistic assumptions it turns out that next generation giant telescopes could benefit from this technique and could not require any Laser Guide Star.