Possibly one of the ironies here is that even to engage in a discussion for the proposition "there is no highest good" or "there are no supernatural gods" you are necessarily entering into a playing field of abstract logic where you are accepting definitions which do not map perfectly to reality. Did Epicurus do that at times? Apparently, so as to show the way out of Platonic logic traps, but it seems the later Epicureans felt forced to do so more frequently (as cited by Torquatus) and even though they perhaps fought fiercely to maintain Epicurus' original point as well, it's easy for establishment victors to preserve only what they want to preserve.
I do think though that when "other" Epicureans went so far as to admit a fourth leg into the canon, which seems to me to have been done as an accomodation to "logic", was a fateful and fatal mistake.