??? Are you going by who had the last word in your decision making? That'd be very unfortunate for you. You will never make a decision or a prudent one anyway. Do you think you are talking to only experts here? Everyone's an expert? Think again. For every expert here (like in any field or forum) there are 10-100-1000 ignorant ones, me included.
IMHO: Never believe anyone's word. Not mine, not FuriousFish's, not Rutinis's, no one's because you don't know any of us (yet)! If people point you in the DIFFERENT directions, you can first, figure out who to believe and second, hit "the books, the net" to see who is right or wrong or what.
Look at it that way: 10 ignorant people like me will steer you in one direction and then one real expert or even an ichthyologist comes in and says different. You will brush off the expert's opinion as the minority opinion whilst it is the only correct one. So, until you know who to trust more, you have to figure out who gives the more correct info and the only way to do it is by doing research YOURSELF. If you care, of course... If you look for an easy way out, there is none for a beginner forum participant.
You can very simply start by testing this all-encompassing, wide-sweeping, and absolute statement "Synodontis are very territorial and aggressive." or at least ask for it to be explained.