“These two words can be exchanged/swapped /switched in this sentence.”

exchanged doesn’t really make sense. you can say “can be swapped” or switched. but make it clear you talking about the positions

This is very hair-splitting, to me: Swapped usually means they trade places, or are flip-flopped, or both are there just in a different order Exchanged usually means more of removing one and putting the other in its place Switched is somewhere in the middle between them. Switching something is usually like going from one option to the other and there's nothing about whether both options are present together or only one appears at a time. Maybe your options are what order the parts of the sentences are in, so 'switching the order of the sentence' sounds perfectly fine. "Switched around" is equivalent to "swapped" "Swapped out" would be equivalent to "exchanged". "Switched out" would be the same but that is less common in my area. So to answer your question, I'd say from best to less good: * Swapped * Switched around * Switched * Exchanged

Not sure about exchanged, but I think switched/swapped would sound normal to me. It's one of those situations where the more I say it in my head, the more nothing sounds like real English anymore, lol. If anything, I don't think it would sound unnatural, but risks being a little unclear/confusing? The way you explained in the body of your post is very clear to me, but if you wanted an alternative, you could try adding something to clarify that the words are being switched \*with each other\*, like "These two words can be swapped around in this sentence." (Added "around")