I don't see how these devices are all on the same network, if they all have the same IP address.
If they're all on different networks, then they must be behind NATs in order to talk to anything non-local. In that case, there should be no problem connecting them all to the same OpenVPN server (at least in tun
mode). Each client will be identified by its public (NATted) IP address, and each will be assigned its own address from the OpenVPN server pool. You should be fine in such a situation.
Your only other problem will come if you use 192.168.0
behind the server as well, in which case the clients may have routing issues. Don't do that.