imo the 2 way xover would have split the signals from a tweeter and a mid bass unit, either a 4", 5 1/4" or 6.5".
the three way xover would have split a tweeter, a 4" mid and a 6.5" midbass.
the problem you'd have if say you were using these to power a set of mids and tweeters on either side is that the three way xover, which ever way you wire it, will have a gap in the frequency range - either the lower end that the 6.5 midbass is meant to play, or the more vocal frequencies that the 4" mid would play. if your going to use them then id say sacrifice the 6.5" from the 3way.
If your not planning to run components from them but say, 6 x 9's then im affraid their useless as you'd not be able to provide the correct frequencies.
Hope some of this helps