There are N+1 "X Basic Plots" archetype systems for classifying fiction. N is the number of people who have decided they need to categorize plots and 1 is the latest person to have done so & X is the number of subdivisions the classifier felt like making. Since these are largely written retrospectively they all have a very similar consistency to them, the archetypes are generic enough and familiar enough that you can apply them to the 'universe' of stories that exists. Like an astrology chart for literature, enough handwavium and will to to apply the system will get you quite far in establishing any system's universality.
A Stranger Comes to Town has been around since at least Tolstoy (and I don't even need to research it to know much, much longer); but there is no actual rule as to what must happen in such a story other than "A stranger comes to town" ... and "something" happens. For the purposes of writing, unless you want to understand a specific archetype's definition out of a specific method; it's super hard to answer this type of question. Sometimes, with a formula, you can grow a new but similar read; but, that's not really because all stories are governed by the formula. A story boiled down to it's formulaic components can of course be reconstructed with different players for effect. As a writing technique, it is a way of getting to story that will work in a reliable way; certainly important when you try to sell.
For a moment, before we abandon this project as we should, let's engage plus-one-ism. What does "A Stranger comes to town" consist of?
It consists of a place, a group of inhabitants that know each other and an unknown entity coming to town. Any story has conflict, so it's probably worth assuming the stranger will give rise to this conflict; either as a catalyst (being largely unchanged and reflecting the character of the town) or as the flame striking the match (being either a protagonist or antagonist). Well, that's already three very distinct types of story and there are all sorts of considerations that might go into each. And we've already chosen to neglect the stranger who comes to town and just spectates on other people's problems.
And now we come to the problem. We don't know what you mean by "Stranger Comes to Town" other than that generic set-up which could lead almost anywhere.
There are no requisite beats to such a story. You make decisions, and then you follow the standard architecture of story: Characters, Conflict, Loss & Gain & Change, Conclusion.
This particular archetype division is a bunk false dichotomy to begin with. Stranger in a strange land & stranger comes to town precludes ever telling a story about people who happen to already know each other; of which there are plenty of stories. Do both of these types of stories exist? Yes, and largely they are complements of each other. They do not split the sum of everything neatly in two.
All of that said, this phrase has been in used in specific ways. Here is an example of a breakdown of some existing story tropes. It works, and there are beats, but it is not a rule that stories must be written this way. You likely could with much academic research write a book like the Hero's Journey for this type of story; someone probably has.
A Stranger Comes to Town (Classic Western - Also Samarai/Post-Apocalyptic Secret Sauce)
- Beat 1: A Town Has Something Wrong With It, Is Set in Its Ways - Establish that the town exists, show it's primary problem and the consequences for it remaining the same. Perhaps that's as bad as death or perhaps its just some locals suffering under the rule of normal.
- Beat 2: A stranger comes to town. A person of various, but clearly different origin shows up in town. Where and how is not particularly important so long as they hold the key to the town changing and being acknowledged as being apart.
- Beat 3: The stranger is confronted with the problem facing the town and [pick several options] decides to fix it, decides he'll move on, can't leave because he must do something first, has nothing to better to do... something.
- Beat 4: The results of his choice probably fail and we see how much worse it can get.
- Beat 5: Protagonist makes the right choice to help (or is forced to), "accepts" destiny (classic midpoint); but has lots of work to do to get to a satisfactory conclusion. Enter a try-fail cycle?
- Beat 6: The stranger or town can't save itself until some sort of emotional thing happens between two parties.
- Beat 7: With the emotional conflict resolved, the stranger or people inspired by the stranger band together to change things once and for all.
- Beat 8: Changing the place.
- Beat 9: Dealing with the consequences of changing the place.
- Beat 10: The stranger leaves.
Did I just make up all of that? Meh. You be the judge. I thought about some westerns and a lot of bad 80s television and wrote down the major points of decision and conflict. I'm sure you can work pretty hard to prove most stranger stories somehow fit that structure if you want to.