Yes, like I said YMMV
On some routes (and depending on what your sales city is) you may find under the same FQ transaction fares for the same class but different family code, and even fares with a given family code but attributes of another family...
It we were in pre-2012, I would definitely assure you that every class is always in the same family, but not anymore.
At least UPG elegibility is still based on the family code in the fare basis (LE in your example) which at least makes some sense for the passenger and ticketing agent. Pre-reserved seats are restricted on a city pair + booking class basis, which is a nightmare