It's not aggression, it's a feeding strategy.
I've seen it before in melanura and hetros.
They sneak up on the victim and pinch a scale.
Once they get a taste for it it's hard to stop them.
I never knew this was a thing with them. I have just one male in a community tank, and never kept more than one.
It's kind of funny to watch him get chased by a 5" male meeki. The size difference is great.