And, referring to the pircha PAA bought against yekke2 regarding Grindelwald, if possible I would like to make a similar vort to the one I made a while ago about House-Elves. The act can either be through defeating the previous owner, or physically taking it against their will. And the physical act, like by Grindelwald, negates the need to defeat the owner by force.
But, yekke2, what PAA appears to be questioning in the earlier post referenced above is not the process by which it (Harry gaining mastery of the Elder Wand) works, but how Harry was aware of that process. The process makes sense (not that there aren’t any valid questions, simply that the process stands up to scrutiny), but how did Harry know? And whilst I have made a stab at answering it, it is a very pertinent and difficult question.