I think the thing that has helped me in the compatibility compartment is the addition of fish at small sizes. All fish are now no bigger than 7-8cm other than the 2 BGK's, the sailfin pleco, 1 angel and the gold spot. I'm going to be adding some Corydora's of varying types (around another 15) as the experiment with the addition of the 4 so far has gone well, they have been in there for 3 months and haven't lost 1 yet. I think that the other thing that helps to is the amount of driftwood, plants, types of rock and the way I did the background have helped out as there is area's for each to have their own space to hide away from the others or with their own type and a free swimming area. However again I think the best thing I ever did was add a couple of fish at a time every week or 2 at young ages as they have seemingly grown a tolerance for each other, although I did have a problem black shark which was sorted out by the biggest of the 2 BGK's. Unfortunately I don't have a digi cam but am endeavouring to get 1 so will post photos when availible.
Cheers,
Bryce.