Mergers then and now.

[naraht]

Looking at some of the mergers in the various councils over the years, I've seen the following cases
1) active chapters of both on the same campus (leading to merger, or in unequal mergers one released)
2) active chapters don't have overlap, but charters overlap with either one active, or neither
3) no overlap at all. These are often mergers of regional groups to make a stronger national one.

For the current three largest councils...
For the NIC, there do exist members that could do an no overlap merger, for example, (even though their focuses are completely different) Tau Phi Sigma and Beta Upsilon Chi
For the NPHC, As far as I can tell any pair of groups there (even of different genders!) have dozens of campuses where both are active.
for the NPC, I *believe* that it is the same situation as the NPHC. I believe that either all or all but a few have chapters at U of Illinois and that other campuses are close enough to "full" that I just can't see any possibility without massive chapter mergers.