Here is a video the king put up 4 months ago on Youtube. The tank is 96x48x30 and during the video the Armatus swims the width so I am thinking the beast is 30"+.
Trust me I would if I thought there was any possibility I'd get away from it but these are two species that are too predatory and I know there would be losses.
DB, your inbox is full...
I find that cohabitation relies mainly on individual personalities. I have a spotted bush fish who lived happily with piranhas for 5+ years so I say anything is possible