TL;DR: Here are the queries:
This can be done using SEDE! However, to be clear that there is a slight limitation in that SEDE only updates once every week.
How often is the Stack Exchange Data Explorer updated?
The data is updated early every Sunday morning around 3:00 UTC
Data Explorer, Using Data Explorer, Frequently Asked Questions
I have used a query previously that tracked gold tag badge progress. Before we get in to the queries the following is important.
They are different to "Top Users" as it takes into answer count as well.
They don't take into account question count/score... this may be desirable to someone
The factor to make the score and count be more evenly matched may need tailoring slightly.
With some slight modifications to it I have come up with the following query for: Top users in a tag by score and answer count. The results of this query for our top tag story-identification are:
Modifying this with the help of a user on SO we get the following query which brings back the top user in every tag, in the case of a draw it will bring back all top users: Top user in all tags by score and answer count. It currently looks like the following at the top:
And then for a bit of fun I modified it slightly so that it takes a user id as input and tells you what tags that user is top in: Tags where specified user is top by score and answer count. Running it for our current top user, Valorum, we see, this brings back an impressive 642 rows: