True that Jardini get their reputation of being very aggressive but it all depends on the fish itself but MORE than likely it wont happen unless you have a very peaceful jar. That is a very nice tank and basically go crazy with your arowana stock!
It's possible. People just been reading too much about the jars reputation of being the most aggressive aro. Jars got the same aggressive level as the asian aros. Flaring and biting would occur and that happens to asian aros too. This is the risk if you plan to keep aros in comm. Even silver or black aros would do this kind of behavoir too.