Connection to SPserver

if they are in the same subnet you don't have to route using yur firewall for your clients and servers in this case already know the route as they have an interface in that subnet.

if they are in different subnets they have to  have the firewall as default gateway. In this case you need on your firewall:

- secondary IP in the other subnet

- Policies to allow the traffic

you still need no routes, they're already there with the interface ;)