I think I've heard the exegesis in the OP before. About the Israelites spending 40 years in the wilderness to train militarily.
This might be a strong candidate for the worst exegesis ever. I guess it goes - it's pretty ridiculous that God would make them stay in the wilderness for 40 years, but the 40 years must be the historically correct part. So they must have spent the 40 years preparing to invade Canaan. It seems to me that one of many many problems with that, is that if you start training when you are 20, after 40 years you will be 60. Oh well, as they say in politics, stupidity is not a crime.
However on a more serious note, I think gorilla warfare deserves some attention. This recalls the
Sokolsky_Opening in chess - also called the Orangutan.
Perhaps its most famous use came in the game Tartakower versus Maróczy, in the New York 1924 chess tournament on March 21, 1924.[2] The name "Orangutan Opening" originates from that game: the players visited the Bronx Zoo the previous day, where Tartakower consulted an orangutan named Susan, and she somehow indicated, Tartakower insisted, that he should open with b4. Also Tartakower noted that the climbing movement of the pawn to b5 reminded him of the orangutan.
Also, I've heard that Tartakower made some reference to Orangutans "killing by encirclement" but I'm unable to find a clear source to confirm this.
Anyway, perhaps the Israelites used the Orangutan idea at Jericho, which perhaps contrasts with the Guerrilla tactics at Ai.