Is your viamingi that aggressive? I had one in the past that was aggressive. Not major damage, but lots of tail wagging. The viamingi I have now is more mellow but lets every fish I have, including trigger fish, know he is the boss. Funny.
I was thinking about getting a sohal. I printed a nice life size photo of a sohal to see what the viamingi would do if he saw it. When I place the picture of the sohal against the glass, the viamingi bolts into his hiding spot.
Meanest tang I ever had was a purple. Killed an achilles and a regel!