First impression: they sound stuck-up. (but that kind of feels inherent to monarchy? Probably a good name?) The primrose guard is the “elite force” that hasn’t seen real combat and gets their butts handed to them by the filthy commoner mud-people peasantry freedom-fighting force that they’re constantly disparaging as “mud bandits”.

I think it would be hard to find a flower name that conveys toughness, despite the matriarchal aims.

That said, it’s your fiction, it’s your world, and it’s your story that will shape the audience’s opinion. This is a context-free first impression.