Exactly Dangerdoll...
IMO keeping pets is about providing them with the best conditions you can, with the information you receive, that is most like their natural habitat, as they have evolved to live with certain needs. If you have $ to throw into fish, and you have the resources here and on the internet, all of which advise pretty much the same, I think you should follow the advice to the best of your ability. Experiencing or living through someone else's experience is valuable. I had 4 cories down to three now, they swim and eat and try to school, but they were calmer with 4 and I can tell you soon how they'll be with over six, as I am getting more. I think species may make the least difference, but I told what I thought was the perfect scenario. I would not buy fish that I was told to put into a school if I didn't have the intension of getting the appropriate #.
So that is where my answer is coming from. I stress over the mistakes I have made. I figure I should pass on what I have learned.