Six of one, half dozen of the other. I've done it both ways. For me it comes down to which is going to be easiest and/or cleanest to layout. The tube connectors can handle up to three of the 16ga wires. If I have more than one wire going into the tube connector I twist the wires together before inserting into the tube connector. On the NX-Otica networks I just built, each of the three sections had their own positive and negative leads going to the tube connectors.
Also, when the polarity gets reversed at the driver(s) there are two ways to do the color coding: (1) code the wires coming off the network toward the drivers so that white wires connect to the negative poles of the drivers and red wires connect to the positive poles i.e. reverse the polarity with the color coding; (2) color code the wires so that they correspond to the tube connector (from the amp) so that the red wires coming off the board are connected to the positive tube connector and the white wires are connected to the negative tube connector then reverse polarity at the drivers as necessary.
I find the first method confusing when reading a wiring diagram that shows the polarity being reversed at the drivers. Plus if I or somebody else has to work on the network later and either forgot or didn't know the color coding had been reversed it could be a headache so I prefer to use method 2, Keep the color coding consistent with the amp input. Either way works, it's just which you find easiest to work with.