No ofSerial only opens a connection to one device, it just holds a vector of available devices to connect to. You would need a separate ofSerial for each object you want to connect to, like you have already done when you hard code the ports.
Certainly take a look at how the setup in ofSerial works
do you know how many devices you will have or do you need a dynamic container like a vector. If you need to have a variable number of connections I would probably iterate through the devices and then make a new serial object rather than passing pointers when the device completes the handshake.