The Sweboz

[athanaric]

That certainly seems reasonable, moreso if availability for other factions is considered (everyone can recruit the Arab guys at tier 1).
In fact, the Jugundiz are almost identical to Immanae (who are sort of generic Barbarian skirmishers), with the only difference being a better shield and IIRC a somewhat less clumsy spacing. The Balroae might fit into this category as well, having better morale but a small shield - and they are only available on the dark side of the moon.

In fact, we could probably group the "hidden badass" skirmishers into a top group - Komatai, Bedouin skirmishers, and Baktrian Hillmen - and a second, slightly weaker group, which includes the Jugundiz. Balroae could be with either, dependig on your taste.