Adding battery stack 2 to EG4 18kpv?

I have 6 Ruixu batteries hooked up to the EG4 already and they are working fine.

Just bought 3 Eco-Worthy batteries that I want to hook up and plug into the battery 2 hookup in the EG4. I am assuming that you can do this as they do supply a second plugin point. Don't know for sure and they could just be a parallel battery plug in.
Also wondered about which Ethernet plugin you plug the communication cable into on the EG4 from the Eco-Worthy batteries.

Thanks

Greg