The Control appliance has a 1gbps Ethernet interface so that can plug into the switch without wasting a higher throughput Ethernet interface.
For the 2 computers that need 1.5gbps, you’ll want to plug those in to L1, L2, or L3 (assuming they have greater than 1gbps Ethernet interfaces). L1, L2, and L3 are all 2.5gbps Ethernet interfaces.
If you have an actual fiber output from the ISP, you’ll need an SFP+ module that’s compatible with the ISP as well as the Route10, put that in W2 and you should be all set. For the Route10 side, generally anything advertised as Cisco compatible should work.