Nice choice, Trust me when you lose one of you're Armatus you will bash you're head against the wall, Anyway atleast we won't have to worry about more Armatus deaths, The payara market is not doing too good lately and you're Armatus might be worth alot more money in one more year.
The armatus currently are too big for him to harm, its my Tiger Fish I am worried about, but problem solved he is currently in a different tank until I feel fit.