Upvote:3
In this site, this kamon is named as Hiraoshiki Kenhanakaku. Kenhanakaku means "Sword flower horn". It is a variation of the Hanabishi.
Generally I think you will find crests being used by different clans as they adopted symbols and crests from previous/other clans with which they were affiliated or to establish their legitimacy. For example a similar pattern is found in use by the Goto clan or Uku clan.
These two pictures downloaded from here have the Goto clan and Naito II using mon with a similar pattern: