I really think removing the joined trill would be the best solution, it isnt really canon that I can tell, and giving it the same trait as the joined trill, with a new name totally fits with the augments. I really think Cryptic should do this, Im amazed they didnt think of it!
The idea is that Curzon Dax was a well respected Trill ambassador among Klingon circles. He lived like a Klingon and earned their respect. Jadzia Dax was also respected by the Klingons because she is "the heir" of Curzon. Both were considered Klingons despite not being born Klingon. Joined Trill as part of the KDF are suppose to be part of this tradition (Symbionts that have earned the respect of the Empire).
however Im still a firm believer that they should just remove the joined trill from the kdf and make it the augment klingon. Any joined trills would be grandfathered in, and could possibly become a vet reward.
well if a joined trill is canon for klingons, I say add the tos ones anyway, with a diff skills set. Remember they were very smart and strong but arrogant as well in an extreme.
Why "waste" the resources? Its bringing the klingon faction some rp flavor...
But you can already RP as a Klingon augment using the alien species and you get to choose all the traits. IMO it doesn't get better than that. I wouldn't want some BS trait assignment the Devs come up with when I can pick my own. Use the resources to flesh out the KDF in other ways.
You're obviously not the target market for this then. No one said they'd take away the ability to use the alien species to do just that. If there is enough demand, the devs will add it in because it's either something the players want and they'll give it to us or it's something that enough players would buy and the work would pay for itself.