It’s just that “poem” isn’t “pome”, but “poe-em”. Not the same sound you have with “doe”, for instance. And that just made me think of “does”, “duhz” the verb that is, not the plural noun. I had better stop now. “Canoe.” Stopping NOW!
Lol. The ‘o’ in poem makes as /O/ sound. That was the point. ‘Does’ is irregular but ‘canoe’ is not an english word and wouldn’t follow an English rule.