I can't have them all connected to the same block, since the tubes have to connect to the bottom of the generators. Although I could try having five relays connect to the same tube and have each relay lead to one generator if I can't think of anything else. Hopefully there's something more compact, but I'll go try that out now and report back. (EDIT: The relay idea does work, so there's that possibility. EDIT EDIT: Also works with transposers, forgot I could use them in that situation too. Much cheaper)
A sorting machine won't work, unfortunately. Since I'm only feeding one type of item through it it'll only tag it one color, even if I have that item in multiple columns (I tried that exact thing for a different system).