I keep my 10" Jardini with 4 bala sharks (6"), 9 tiger barbs (3"), 1 african knife (8"), 2 bristlenose plecos (4"), and 2 emerald corydoras (3"). The tank is heavily planted (with CO2 injection) with plenty of large driftwood. Hence, the other fishes have plenty of hiding places in case my Jardini decides he wants to go medieval on someone. In the past 12 months, he's only killed 1 bala shark.
I do keep him VERY well fed with giant mealworms and Hikari carnivore pellets. He also loves snacking on the tubifex and bloodworms that I feed the other fishes. He normally doesn't even give the fishes another glance. Just ignores everyone and goes about his business. When he sees me approaching the tank, he knows he's going to get a treat so he just stays right in front of the tank like a puppy dog. Maybe I'm just lucky...but never had any behavorial problems.