I agree that they are all still so confusing to me as well. I am not particularly interested in learning them, but I do like to try and keep them straight as I live in Japan and KFC is funny to say, well the guy is actually 大佐 Sanders (or is it 中佐 or… AUG_H)
Easiest way to avoid them is what @soggyboy said and give them a synonym called “military” and that way just blast through them. If you understand they are military and you don’t ever need to know the distinctions then that’s perfect.
I will say there are a few people who have different ideas of what should be removed and what is uncessary and what words they see a lot. I can see people who play video games surrounding war generals or have a general interest in military wanting to know these words in Japanese. Plus, it seems that the 佐 kanji is used mostly in military words, which makes sense why WaniKani put them there. I think they have only ever removed a few vocabulary before, but they usually will not remove vocab unless it’s extremely outdated or old Japanese. These military terms are still being used so best way to not review them, is to do the synonym work-around