Programming is one of the most essential skills of a game designer : you have to be able to know whether your concepts can be put in practice, write technical documents and be able to communicate very well with programmers.
Without that, the likelihood of pushing interesting team projects to completion is low.
Yes, there are many things a game designer should know about, but the technical aspects of the job are by far what will take most of your time.
Moreover, leading a team requires strong leadership skills, including the ability to take decisions, handle conflicts and take responsibility for failures.
If you have little experience there, I'd recommend that you at least take several months programming little games from the ground up and look at the templates and tutorials provided with construct 2. You can also dig resources like Codecademy for a progressive introduction to the world of programming.
Take care,
Nathan