The only real problem I can think of is excessive turbulance. If you see fish struggling to swim, or getting blown around the tank, it's time to redirect the flow of some of your filters.
Angels are fish that don't like too much turbulance. If your angels are ok with your filtration, then the rest should be fine with it.
Most filters are rated with no media, after you add media and it gets a little dirty, you are probably decreasing the flow by 20%. That means your pair of filters are probably filtering around 530 gph. I have a 55 full of larger angels that has 625 gph between 4 filters, none of them mind it. If I directed the flow of some of the filters across the middle of the length of the tank they would get knocked around pretty good.
