I made secondary and third channels (even fourth and fifth) for the topics that are not fitting the my main channel and I don't regret it. So the subscribed people interested in gaming will not get non gaming videos in their feeds and the other way around. And since YouTube broke more than one thousand of my videos, I will not confuse the viewers by re-uploading the same videos over and over again. I just re-upload them on the secondary channel, and the main channel stays stronger than ever (despite YouTube's negligee on fixing their bugs).
With that being said, the fourth and the fifth channels are total disasters and they will hardly reach 5K total views in the next 2 years or so. My experience is good with two-three channels just in case, but not more i.e. don't spread too much.