The requirement to fuse is found in the manufacturer's instructions for that specific piece of equipment. Still, that only means that there has to be a fuse somewhere in the circuit.
If the nameplate reads "fuse," rather than "overload device (or some such), then a fuse is needed; a breaker is not sufficient.
Otherwise, the disconnect has to be mounted as the code calls. There is no rule against having more than one disconnect; many times I have seen the fused disconnects at the control center, while there was a second disconnect mounted right at the equipment.
