After bouncing it around for a while, I think using any dirty tricks at all on Kaifun would only reinforce his narrative of military members as worthless bullies, and it would have to be a situation where a fight was at least partly his idea in the first place as well. Or if he somehow agreed to accept a spar, since doing it as actual lessons is probably out of the question given the differences in his kung fu and Garrick's Juraian sword style let alone his attitude.
Alternately, does it have to be Garrick who administers an attitude adjustment? Directly, I mean. If more people are being added to the population of Macross City specifically in the name of preserving knowledge, it wouldn't be strange to have at least two or three martial arts masters included, and if one happened to be from a senior school of Kaifun's style he'd probably be more inclined to listen to that person than some military wardog. Garrick could still be involved in the scene on the premise of seeking to expand his swordsmanship by practicing against other skilled martial artists, or to brush up his unarmed combat in case a blade is unavailable or lopping off bits of the opponent is undesirable.
Alternately, does it have to be Garrick who administers an attitude adjustment? Directly, I mean. If more people are being added to the population of Macross City specifically in the name of preserving knowledge, it wouldn't be strange to have at least two or three martial arts masters included, and if one happened to be from a senior school of Kaifun's style he'd probably be more inclined to listen to that person than some military wardog. Garrick could still be involved in the scene on the premise of seeking to expand his swordsmanship by practicing against other skilled martial artists, or to brush up his unarmed combat in case a blade is unavailable or lopping off bits of the opponent is undesirable.