It's better to have seprecate channels if the content is different.
Many people think having everything on one channel is better because you'll have twice the audience. But from my eom experience, it doesn't work that way.
When people subscribe to your channel, they are subscribing for certain content. (Vlogs, gaming, skits, etc). When you start throwing in other genres, chances are they don't want to watch that. That's not what they subscribed to, and they will most likely unsubscribe. Ive unsubscribed to many channels because they started uploading content that I wasn't interested in.
When I started my channel I was making vlogs. When I began to make gaming videos on the same channel, I started to loose subscribers pretty quickly. Those people who subscribed for vlogs did not want to watch gaming. Once I decided to create a new channel for my gaming, I stopped losing subscribers. They became more engaged with my gaming channel than on my vlog channel. It was a good move on my part.