[cjhveal]

I think these are cases where it's going to depend on what is most natural for each individual, especially when used for mnemonic purposes. Whether the acoustic or articulatory similarities feel more salient is going to depend entirely on your own mental model of the language. It's common to see the unvoiced dental fricative realized as /f/, even in native english dialects, so if that is more natural for you to remember, there's value in that.