The Zoramites Became Lamanites

Dear Austin,

For behold, it came to pass that the Zoramites became Lamanites; therefore, in the commencement of the eighteenth year the people of the Nephites saw that the Lamanites were coming upon them; therefore they made preparations for war; yea, they gathered together their armies in the land of Jershon. - Alma 43:4

The other day I was led to this verse.  The first line stopped me in my tracks.

"...the Zoramites became Lamanites..."  

The situation of the Zoramites has fascinated me for what feels like several years now.  Their entire situation leaves me so much to ponder.  How is it that an entire city, or group of people, so easily can join in with a group of people esteemed as their enemies, for so long before?  It seems like an easy transition, because shortly after, the Zoramites are coming against the Nephites, with the Lamanites.  What is it that allowed them to acclimate so quickly?  Just curious.  Was it because their sins were the same?  If their worst sin was the oddity of their pompous prayer, their worship only on Sundays, and the costliness of their apparel and their shunning of the poor, how is it that they fit in so quickly with the Lamanites?  

~Mom<3