I picked up 4 back in April, you'll get maybe 2 months of them getting along (maybe even less time than that). One or two will grow way faster than the rest and will relentlessly beat the others up, especially when feeding. Just be sure you find a place for the others when that happens. I luckily had another tank set up and ready to go, so I was able to split my 2 favorites with a divider and move the 2 smaller ones into another tank.
They really are violent towards each other, so just keep an eye out on the situation. Hopefully you can sex them and pick your pair before any issues come up. Cute little guys!