Reddit doesn't allow subreddits to limit who can moderate posts or comments except by taking the subreddit private and limiting the membership.
It's actually a bit of a major pain, particularly for smaller public subreddits.
Reddit's moderation system in general is just hugely problematic. It kind of works, but it really doesn't, and has received very little love.
The first question for any such system should be "what is your goal?". Reddit serves popularity relatively well. Accuracy, relevance, information: rather less so.
Some non-brief thoughts on that from a few years back:
https://www.reddit.com/r/dredmorbius/comments/28jfk4/content...