That setup doesn’t work because the two Whonix VMs are very securely tied to each other. I’m assuming that the pfSense VM is running a VPN client. In order for the VPN to connect through Tor via the Whonix gateway, you need to specify the SOCKS5 proxy. In the Advanced box in the VPN client setup in pfSense, add two commands:
;socks-proxy 192.168.0.10 9050 /usr/local/share/up
In /usr/local/share/up, put these two lines:
changeme [or whatever you've changed it to]
In order for the Whonix workstation to connect through the VPN rather than through Tor, you need to disable all of the settings that point apps through the various SocksProxys on the Whonix gateway. I’ll leave that to others.