I participated in the naming efforts for a few Sikorsky types, it is not a game for the faint of heart, when closely scrutenized, every name sounds foolish! Names come from either the manufacturer (for civil aircraft like the TwinStar) or the military organization that paid for the design (like Black Hawk or Iriquois). Numbers come from the manufacturer when they designate the sequential model number (S-76) and come from the US military service when they are type/model specific (UH-60L, MH-60L, SH-60M).
I think the nick-names they get from their users are the more durable and memorable, like Huey and Snake, Jolly or Thud or Buff.