Ok, I noticed that the medical cross on it differs from one town to the other, and comes in every color. At least in hoen it does.

Anyone know why this is?

So people can tell the Nurse Joys appart.

Even though Brock doesn't need any help.

I think they're all clones with different hats.

I don't see how that'd help. I still wouldn't be able to tell them apart.