I really think both sides of the coin have something to offer. One thing I like about larger communities is just the shear amount of content and discussion you can see, especially if you have a lot of time to kill. That being said I am VERY much enjoying interacting in a smaller community - haven’t done that in like a decade.
Ask Historians relied so much on people with actual expertise that I think it’ll be hard to run something like that with the community being so small.