@Martin yeah, that is fine. Thanks.

For a long time I did not notice that the table Tags contains Count - and in many queries I actually counted the questions. Of course, I still need to use COUNT if I want answers, non-CW questions, closed questions or something else - but at least the total count of all questions in the tag can be read from here.

@Martin I expect count to be there for performance reasons as count is shown on the tag on-hover dialog, that gets loaded dynamically from the server. I know this then leaves the question: why isn't the watcher/followers count in the public schema then? Not a clue. It might well be in the real production schema of the db. getting the follower count can be done but a bit more cumbersome: meta.stackexchange.com/q/274618

Recently there was this question on Mathematics Meta: It is possible to incorporate in the Tags main page the additional filter "Watchers"? Because of that question, I checked whether the SEDE contains number of watchers/followers.