These are what St. Thomas Aquinas calls "ambushes" (insidiis, the same word used in the St. Michael prayer that's translated as "snares") in Summa Theologica II-II q. 40 ("On War") a. 3 ("Whether it is lawful to lay ambushes in war?"):
The object of laying ambushes is in order to deceive the enemy. Now a man may be deceived by another's word or deed in two ways:
Nor can these ambushes be properly called deceptions, nor are they contrary to justice or to a well-ordered will. For a man would have an inordinate will if he were unwilling that others should hide anything from him
- through being told something false, or through the breaking of a promise, and this is always unlawful. No one ought to deceive the enemy in this way, for there are certain "rights of war and covenants, which ought to be observed even among enemies," as Ambrose states (De Officiis i).
- a man may be deceived by what we say or do, because we do not declare our purpose or meaning to him. Now we are not always bound to do this, since even in the Sacred Doctrine many things have to be concealed, especially from unbelievers, lest they deride it, according to Mt. 7:6: "Give not that which is holy, to dogs." Wherefore much more ought the plan of campaign to be hidden from the enemy. For this reason among other things that a soldier has to learn is the art of concealing his purpose lest it come to the enemy's knowledge, as stated in the Book on Strategy [*Stratagematum i, 1] by Frontinus. Such like concealment is what is meant by an ambush which may be lawfully employed in a just war.
Randal Terry's strategy is that of #2, and it seems his is the best one that stays within the realm of moral action.