In Langenscheidt Großwörterbuch Deutsch als Fremdsprache, I read the following usages of streiten in the sense of quarrel:
As an intransitive verb: "Er stritt mit seinem Bruder um das Spielzeug." (quoted from Langenscheidt)
As a reflexive verb, sich über/um etw. streiten: "Sie streiten sich um nichts und wieder nichts." (quoted from DWDS)
I am wondering whether there is any difference between the two constructions?
A wild guess that occur to me is that:
The (ordinary) intransitive construction über/um etwas streiten applies to such cases as there does exist some reason for the quarrel; for example, children quarrel over who is entitled to a toy, heirs quarrel over who is entitled to the estate, or roommates quarrel over whose turn it is for tidy-up.
The reflexive construction sich streiten seems to connote a quarrel which is of much ado about nothing, when at least in the eye of the speaker there is no real reason for the opposing parties to quarrel; e.g. "sich um des Kaisers Bart streiten". (This is an idiom given in DWDS, which means um etw. Belangloses streiten.)
Could anyone help with this question or deliver any comment on my wild guess on the possible difference between the two constructions?