The men of Ephraim were gathered together, and passed northward; and they said to Jephthah, Why did you pass over to fight against the children of Ammon, and didn't call us to go with you? we will burn your house on you with fire.
Such criticism takes no account whatever of the device of retrogression in telling a narrative.  There are thirty examples of this same phenomenon in Sir Walter Scott's "Ivanhoe."  Here, the narrator, whom we believe to have been Samuel, merely went back to the time prior to the demobilization of Jephthah's army in order to relate this account of the war.  If that is not exactly what happened, then the demobilization of Jephthah's army had not taken place until the events related to Jephthah's vow had been resolved.  In our view, the fact of Jephthah's gathering together, "all the men of Gilead"  (Judges 12:4), does not refer to the recruitment of his army but to its deployment against Ephraim.  In any case, there is absolutely nothing wrong with the sequence of events related in these chapters.