Things like this can work out, I recall either puffer freak or puffer punk had a puffer community made up of SAPs and DPs. However both the guy in the link and the above had the advantage of a number of tanks and enough media to instantly cycle them so that if any aggression occured they could be moved.
This is similar to the Minions keeping a bichir and a couple of plecs with Marth the Fahaka puffer (reknowned as the most psychotic of puffers). They have plenty of space to move them out if need be.
IIRC you only have one other tank to the one you are looking to stock, so I would avoid any potential disaster such as this. While it may work for a few weeks, even a few months, it only needs to not work for a minute and you've lost a lot of stock.