Hello DANGERTASTIC,,,,,,,Your bike , VZ800 Marauder, has two carbs with one of the cable coming from your throttle ( the pull cable) this cable comes to the left side of the front cylinder air box where it splits ( the splitter) into two separate throttle pull cables one going to the front carb and the other to the rear carb,,, this is an important point when sync`ing the carbs as the two pull throttle cables must be adjusted to the same length,,,,,,, You say
"So you just ditch the cable with the splitter and call it a day"
you won't be able to ditch the splitter mate, you will give yourself a shit load of problems there are 5 cables going to/between these carbs and syncing can be a pain,.
There is a short return cable connected between the two carbs and the second cable from your throttle (main return cable) should connect to a cam that the short return cable ( between the carbs) connects too at the front carb with spring pressure giving the throttle return. If memory serves you adjust throttle free play at the point of contact between the main throttle return cable and the front carb cam at the main return cable end adjuster, you could I suppose disregard this main throttle return cable as long as it doesn't give you throttle grip free play problems.
Not to sure about this but I believe VL Intruders of the same era I.E carb models only had one carb and later models have fuel injection, if so it would be much easier to do away with the return cable.
Hope this is of some help and good luck.