FIOS ONT wtih Google Mesh

Hi,

I recently removed the FiOS gateway router since we no longer have FiOS TV or phone. Just FiOS internet.  In the interim wating on Firewalla Gold arrival, I plugged my Google Mesh Main Puck WAN into my Ether direct to ONT.  Which works fine but without much security.  My internal network has all google pucks backhauling ether over the same network.  The FW Gold scenarios talks about Google Wifi on one network with the rest of the network on another segment.  Is there any reason why my entire internal network can't be the same subnet?  I have unmanaged switches in place for port density.  I dont' have any switches with Vlan capability on the network.  It's a bit confusing to see the FW Gold architecture talk about two different lan segments connected on the same switch.  Any input would be helpful.