"the ballads (ie Otterburn and Chevy Chase) are historically inaccurate, implying that the battle resulted from a hunt on disputed land."

That is true of Chevy Chase but I don't think it is necessarily so of the Scottish "Battle of Otterburn" in which the Scots simply go into England to "drive a prey". I always just read this as implying that they are preying on the English and their goods rather than hunting deer etc. I wouldn't imagine that there would be recriminations against the Jardines simply for not going on a hunting trip - whereas if they refused to join in on a large scale raid.