hi David Groh, you don’t need to use both of them. you can choose one of them which one you most familiar to be work with. Yes sure we will make this themes compatible with gutenberg for sure.
But there is still alot of question circling on gutenberg release. for example for early release, gutenberg not mean to replace your page builder *yet. its more likely to replace post editor we usually use right now. you can view gutenberg on first release will be like medium style post editor.