If they are different interfaces and not switch ports - then no there is no way to put them on the same network without bridging them.
But the only reason you need for them to be on the same network is broadcast traffic.. They could be on different networks and still access everything on the other network. Just create any any rules.
Do these devices use some broadcast/multicast discovery or protocol that is required that they are required to be on the same network..
If want to leverage your ports for individual devices - ok... But why do you need to bridge them.. Just use 192.168.1/24 on 1 and 192.168.2/24 on 2.. And use an any any rule - there you go these devices can talk to each other for anything other than broadcast traffic.
Bridge is only going to complex up the config, and more overhead for what? Are you doing something that requires broadcast to work? Then get a switch... Really the only time it makes sense to leverage a bridge is media conversion...
Or I had something that required the devices to be in the same broadcast domain, ie the same L2 network.. But I also wanted to be able to firewall between them for some stuff. In that case you would use a bridge (transparent firewall) and be able to do such a thing. But just wanting to leverage the ports on your pfsense box.. I don't see the point of trying to bridge them?