Yes, you can route MIDI between two laptops running Live, I've done it before. The main thing to pay attention to is MIDI sync. Basically, you want to pick one thing (probably one of the laptops or maybe an external drum machine) that is the master MIDI clock source, set it to master, and set everything else to MIDI clock slave.
The way I've hooked it up in the past is with hardware MIDI ports on DIN connectors. I don't know a way to go USB to USB. As you have found, there are network ways to do it also. The DIN connector method is a bit old-school and unsophisticated, but it's also reliable and doesn't rely on wifi staying up or anything like that.
In Live, pretty much all of your settings will be in Preferences on the Link/MIDI tab (older versions might just call it the MIDI tab). Double-check the Sync in and out and Track in and out settings. Remote you might want to leave turned off unless you want to send start/stop messages which might require the remote to be on. If I recall correctly, the MIDI clock slave computer will not start transport when you hit play, and then it will start when you start transport on the clock master. You can change the tempo on the clock master and both tempos will follow the changes.
To send MIDI keyboard or sequence information back and forth, set the MIDI in and out settings on the individual track(s) as appropriate.
Note that we don't like to provide link answers here, since links often go dead and then the answer is useless. My answer doesn't go into all the details, and that's partly because my time to type this is limited and partly because I don't have everything memorized. I have found the Live reference manual to be quite well written, as manuals go. For some topics you do have to jump around a lot. I prefer the web version for that reason since you can follow the links through the manual.