Going through some old files, and in or around 1967 - sources stated that Joseph Gennaro's crew was so big it was broken into two Regimes. Half of the crew - mostly the Brooklyn guys were placed under Jimmy Brown Failla, while the remaining stayed with Gennaro.

So it got me thinking, were there any other crews that this occurred with throughout the history of LCN, and who?

All the time. During the 1950s and 1960s was when there was a lot of splits due to the families doubling in size from the new members and once the FBI started to go after them so they made their crews smaller many of them did.
Example.
Bonannos- Joseph Notaro crew which was Carmine Galante old crew was split in 1965 after Notaro demotion into the Mike Sabella crew, Armando Pollastrino crew, Joseph Zicarelli crew, and Michael Zifferano crews. Notaro crew was the biggest crew in the family for decades, then was split between Brooklyn, Manhattan, Bronx, and New Jersey. A lot of powerhouses came out of that crew all the way up to Sonny Black.

The Fiore Buccieri crew in Chicago. They had interests in Cicero, Berwyn, Lake County, the Near West Side and also parts of the South Side. By the mid or late 70's one crew of the Buccieri group took iver the Chinatown area which was previously controlled by a different crew. Buccirris guy or new capo for Chinatown became LaPietra, while Torello remained as rep for Cicero and the rest of the areas. Usually both groups had one representative on the Outfits board of directors, who belonged to one of the two crews, depending on which one was more powerful at the time. For example, in 1982/83 LaPietra sponsored two members of the Chinatown crew and a third one from the Cicero crew.

Previously there were also other larger Outfit crews wich gave the birth of two or three additional crews, each one with a capo of its own.