What is your network infrastructure that is giving you those poor performance numbers?
Most consumer all in one routers are crap but not that bad. the file server should always connect to the main hub of the network with Ethernet (whether that be the router, a switch or an all-in-one crap box), these days pretty much everything should be at least 1gigabit.
Are you trying to use wifi for everything? that’s a recipe for disaster unless you really know what you are doing and have multiple APs and careful signal strength and channel management
ladfrombrad