dolfan your clowns should be ok with the hawk just give it a couple of days and see what happens it might just be a "this is my tank thing" just to prove dominance. i had the problem with my clowns when adding them it lasted for about 3 days now every body in the tank is cool with each other. keep an eye on them though just in case there is a real problem, it should pass.
hunterdaddy that is the difference b/w a false and a true is the black bands are wider on the true, also the false can be even more docile than the trues. and the true clowns have an extra spine in there top fin.