Having read the list of conflicts, the immediate short story that comes to mind is "The Interlopers" by Saki. It is clear that the feud between the von Gradwitz household and the Znaeym household would count as the conflict between men. However if we read on, we see that there is clear evidence of conflict between man and nature. Look at the way that the storm brings down a tree upon them both:
And before the moment of hesitation had given way to action, a deed of Nature's own violence overwhelmed them both. A fierce shriek of the storm had been answered by a splitting crash over their heads, and ere they could leap aside, a mass of falling beech tree had thundered down on them.
This conflict is something that we see is continued by the devastating ending of the story. We can see that the conflicts of man vs. society and man vs. self are both present in the struggle that the characters have to forgive each other and then to publicly announce that forgiveness. After centuries of emnity between the two houses, they would be going up against others in their household and society in terms of forgiving such deep-seated wrongs, and it is clear that they must go against their own better judgement in order to forgive as well.