The stripped down version of your question is "How much is enough?"
I once had a disagreement with a fellow in the Klan. I thought I had "enough" with 40 rounds, but I underestimated their sense of community and had a tense period with a 20 or so of this fellow's best friends. My sense of "enough" was not informed by perfect foresight.
Whoever wrote that the first rule in these matters is to have a gun got to the core of the matter. You can't know how much was really enough until things are resolved.