In order to address the question, I need to make a few assumptions. If these are invalid, please correct me.
By "expansionist," I take it you mean that the socio-cultural complex defined as "God-ism" [to use a dippy empty title] has a tendency, expressed as an overt desire, to extend its reach across other populations. This is not at all obvious. If Godism is "expansionist" in this sense, it does not, as did Cyrus for instance, wish to conquer other people and allow them to practice their preexisting traditions under new rule (i.e., pay your taxes and bow down before the elite natives, and you can otherwise do as you please). Again, it's not that Godism happens to be expanding effectively because, coincidentally, the Godist Empire is conquering very well at the moment, but rather, Godists deliberately wish to expand Godism for its own sake.
On this basis, it strikes me that the obvious counter-example to the "must have a prophetic figure" thing would be the Aztecs and the Triple Alliance. Not monotheistic, to be sure, but otherwise they pretty well fit your list of criteria.
Now if you define "prophetic figure" to mean any inspired leader-figure of some ongoing historical significance, you're going to be hard-pressed to find any socio-cultural complex that doesn't have these. But if the sort of prophetic figure you're looking for is a singular central figure, a name that acts as a core banner under which the faithful march to war and so forth, there actually aren't all that many examples -- and arguably, most of them are counter-examples.
Consider early Judaism, which fits every one of your criteria very effectively... except that, with some occasional remarkable exceptions, this was not a missionizing-converting sort of complex. Expansionist in every other sense, but not by way of conversion (usually -- there are some interesting moments when people are forced to circumcise at sword's point, quite literally).
And then there are many periods and moments in Islamic, Roman Catholic, Protestant, and Orthodox history when expansionism was emphatically non-violent, to the point that it produced far more martyrs than converts. Does that count?
The problem with producing a lot of real-world examples is that monotheism isn't really all that common, and on the whole, it has apparently happened with prophetic figures of some sort. On the other hand, you'd be hard-pressed to demonstrate that any one figure in these traditions so absolutely dominates as to obscure all others. (I am reminded of the Shi'ite fascination with figures other than Muhammad, the utterly central role of St. Paul in most Christianities until quite recently, and the wide variety of Jewish central-prophet figures apart from Moses.)
I am aware that some have argued -- Karl Jaspers' "Axial Age" [Achsenzeit, if memory serves] proposal is the most famous, though not the first -- that centrally-dominant prophetic figures are an essential characteristic of expansionist, civilizing religions. But there are an awful lot of vehement counter-arguments as well.
In short, I see no reason whatever that you can't have the situation you've described without central prophetic figures if you don't want them.