This.... is actually a quite decent rundown of what in medieval times was known as "baronial warfare".
The small-scale stuff that was an almost-yearly occurrence in many places over... almost anything. Not the big battles for conquest, but, indeed, water rights/access, hunting/exploitation rights, and control over the smaller trade towns.
And always partly "what your uncle Heinrich said about our Nan at last years' christmas party" and much larger factional disputes.
And, as has become clear over the last few decades as digitisation made ever more contemporary surviving documents available for translation .... BILLS!!, of that Christmas party... and who gets to pay them, and who didn't.....
Except the training weapons bit.... That didn't happen.. your survival was up to God's Grace, and while it was customary to prefer taking Hostages, there were also far, far more lower Nobles than Available Spots.... And the less scrupulous never missed a chance to thin out the Competition a bit...
Up until the Nobility got....Soft.... you're still talking about a Caste of professional Warriors... Not quite musclebrains, but very much able and willing to see Option B, C, and D as a valid, and often easier, Option.
Non-lethal settlement of Disputes was an option.... Tourneys, both the original "training excercise" as the much more evolved high-medieval Tournaments were used to settle disputes without actual warfare, in both the foot tournaments and the much more high status Jousting.
But that meant Going Public with your gripes, and had a whiff of "not being able to Handle Things", and a definite risk of losing much more status if you lost than merely duking it out on Saturday Morning in some muddy field, out of sight..
Which...... well... Not the preferred option.