Some operators recommend that if flying a widebody then fly on 3W/1R because pilot eye-height is much higher than smaller aircraft. Your wheels would land short if flying 2W/2R. Hope this helps.
That is not right, Richatom.
The difference between flying 3W/1R and 2W/2R is maybe 7 feet difference in wheel clearance crossing the threshold.
From Jepp:
A one degree progressive incremental spread from the outermost to the innermost light unit about the standard approach angle provides the visual guidance...
...PAPI is a point source aid. Thus a non-standard approach will not significantly alter threshold crossing height; only the approach angle will change.
The way you fix a problem of 'wheels landing short' as you put it is not to fly a steeper angle to the same aim point... you move the aim point into the runway. Such as the ozzie airservices people are doing at dunnunda international ports in preparation for the A380.