Think of the TABs as "super-Thorakitai" - nigh impossible to kill, and even more skilled fighters. It would seem to me their fighting prowess relies more on the ability to just push and grind through enemy formations than straight-off killing power, not that they're exactly shabby in that either (0.13 is more or less the overall infantry average lethality, since that's what all the spears and most swords have).

The Cordinau Orca, as Aemilius observed, do indeed have a different sword than most Celtic swordsmen. It's apparently some kind of "proto-sabre" that was popular in the region at the time - the Prodromoi Thrakioi also use it - and uses a different stat-set than the longsword. (+2 attack skill and 0.12 lethality to the longsword's +/-0 attack and 0.225 lethality, to be exact.) I don't actually know much more about it, although now that you remind me I've long been curious about that device - to my knowledge true curved sabres first appeared among the horse nomads of the Pontic steppe around the 6th-7th centuy AD, so even a "proto" type here is quite interesting.