i know that’s what your instructor told you.
They're not always right.
Unfortunately, this is more true than I wish it were. Some people (in any industry really) make themselves more important by inventing or extrapolating information, and imagining scenarios which are remote, yet apparently need great thought and planning to overcome. Engine fires in light singles, particularly with no fuel pumps, are very very rare. In my 4 decades of flying, I know of one, and that was a fuel line left loose on a Cessna 206 which ignited about the time that the pilot opened the throttle. He realized he was on fire at about 100 feet, landed back onto the lake, and stood on the float waiting for help (he coulda jumped in, but help came before he could not stand on the float. Interestingly, the fire extinguished once the fuel pump was turned off, and the fuel valve closed. Though there was cabin smoke damage, on the engine compartment was fire damaged.
Yes, thing about fire, learn the published procedures, and leave it at that. Thereafter, as you are taught, ask for references to the procedures you're being taught (nearly all should be in the flight manual, which you really should read cover to cover anyway. If an instructor is asserting procedures which are not in the flight manual, ask why. What is the authority for those procedures. Though flying instruction generally follows the standards and lesson plan, I have seen some ideas come from other pilots which had a poor basis in reality. Piloting has been around long enough, that if it's important, it's written down by someone authoritative!