Sorry, I missed this. No, they don't seem to be aggressive with each other at all so far. I have 9 right now and they tend to school a lot. Things may change as they get old and grumpy though
I had some that i cought at 3/4" now they are about 1.5"- 2" and i had one kill another, they hang out around the same clump of plants and one day one of them had his fins and one eye all torn up, it died a few days later.