Its OK to run the cables on the outside of the aircraft though makes it a pain to clean at the end of the day, and will sometimes make some strange noises when flying. I would strongly suggest that you seperate your cables. In other words, do not run two cables through the same guide. You are asking for trouble. These cables will chaff each other. You can't avoid the chaffing the way you've run them. Eventually they will hangup on each other. Of course at the most inconvinient time Also you are inducing unnecessary wear and tear on them. If they don't hangup on each other, they will break And you'll loose the aircraft (IMO)
Kevin