Sorry. I love digging in the weeds of language!
No reason for apology at all. As we have AMPLY seen, the translators - even in narrative form - cannot be trusted not to do their own editorializing by omitting or adding words/concepts. The only way to be confident in the final result is to check them.
I do think that we can form a generalized impression of a particular writer -- such as my own views which I constantly revise but that I will list here:
Munro tends to be highly literal but can be awkward to read; Bailey is a more polished version of Munro but is much less to be trusted in his interpretations because he is not ultimately a fan of Epicurus' views; Brown editorializes but frequently seems most trustworthy in interpreting Epicurusso; Smith has access to the latest and best scholarship but regularly editorializes and may be less trustworthy that Brown; Stallings has a good feel for the poetry but is probably not a reliable indicator on deep philosophy; Humphries has a good feel for the poetry but probably goes too far in some of his poetic flights ("the way things are").
Might actually be a good idea to set up a table of our impressions of the various translators. There will never be a way to judge them "objectively" but might be helpful to compare subjective opinions.