It's funny, as I was reading this I actually saw Tango flare at his reflection and one of the nearby corys went like...'AH!' and zipped away quick. Makes you wonder what goes on when you're not around.
I've seen Tango chase them now and again. I've even seem him 'butt' them when they're foraging and he wants to see what they have, but I've never seen him bite them. They've never been damaged in the slightest. It's like he's king of the tank and they know it.
Although one of them just came down the side of the tank and sucked on Tango's dorsal and Tango went... 'AH!' and zipped away this time. Lol!