Options to tether to two ipads?

I have two ipads with LTE. What are my options to USB tether them as a load balance wan connection for Ethernet or wifi users? I have a Slate but open to getting more devices.

Can I use a USB hub to tether both ipads to a single router? Or would I need to USB tether each ipad to a device? And then connect those two devices to a third device via Ethernet and that third device manages the dual wan?

Sorry I never try.

The router can have multiple connections but tethering will need the router to run some program, which I don’t know if they can handle more connections.