While I don't particularly like its use on Clan units, you can NARC for yourself. As I recall, one of BoK books has Phelan doing just that in a Trial of Position (on the other hand it apparently allows him to destory an ASF with a rockslide, so YMMV). Now how the Clans justify TAG, I have no idea.
They justify it by "zellbrigen is for
honorable opponents" -- with the enemy getting no say in whether or not they're considered "honorable", of course. Considering how positively
eager some Clan forces are to claim breach of etiquette and start a melee at the first flimsy excuse, I think the importance of dueling in Clan culture gets a bit overstated by the player community at large. It is an important part of "proper" battlefield conduct under appropriate circumstances, to be sure, but the Clans have never been exactly shy about taking the gloves
off the moment somebody annoys them too much either.
So TAG -- and the artillery that goes with it, semi-guided LRMs still being primarily an Inner Sphere thing last time I checked -- certainly has its uses. They may not be particularly
glorious, which is why those units get something of a bum rap...but they do get the job done once called upon to do so.