Sump is not filtration, a sump is a place to put stuff, equipment such as heaters, pumps, filter media.
And as David R said flow does not equal filtration.
With that pump you have the ability to do a myriad of filtration methods, anything from fluidized bed, to foam fractionation, to adding a refugium all at the same time.
These each could require a separate line that would reduce flow to one area dispersing the energy of the pump.
And you don't specify what kind of fish you plan on stocking.
There are fish that prefer rapids or countercurrent at the bottom of waterfall areas such as Tigerfish of the Congo, or cichlids of the genus Tomocichla from Central America, that wouldn't be phased by the high flow from that pump.
If you want discus or most anabantids, that's a totally different story and you'd need to seriously throttle back flow.
You also have the ability with that pump, to run a number of tanks on one sump, if that is in future plans