What do the different role icons backgrounds mean?

I've gathered a few strike-role trainers. Some have smooth backgrounds and others are jagged.

Is there a functional difference between the two? Do the other roles have variations?

The spiky vs. smooth edges denote a physical attacker vs. a special attacker.

Spiky edges denote a physical attacker with a focus on a high attack stat (especially effective against opponents with a lower defense stat), while smooth edges denote a character with a high special attack stat (especially effective against opponents with lower special defense).

As far as I'm aware, other roles don't have this split.