My totally unfair speculations (but based on available NTSB data):
That sure seems like a reasonable analysis to me. Those situations where the PAPI and the GS differ in close can sure make on path on one look like a float or tuck under on the other.
Like other cases of TMI (too much information) either path guidance will probably be fine to the touchdown zone on an ILS. And, often there is plenty of runway to land a little long or go around, but not enough to indecisively do parts of both maneuvers.