I have to admit, that if someone would ask me which faction to delete, I would answer Saba. I will probably never play as saba, only I play all other civs before(exept for romans :P ) whih could take some time. but still Saba is much better than senate missions. for one, who is arround in the south? AS Carthage and Ptolemies, all of them can be considered "BIG" saba brings a relatively small opponent into the region, although they are not realy expansive, in my campaign most of what they got from the Ptolemies was a gift of mine^^(in fact the only "interesting" thing they did till now was to send a fullstack army against the AS :( ). appart from that they are VERY unique, they don't have those endless Phalanxes, which i've learned to fight by now but realy make expanding into the near east a pain in the ass.
that said, I think the importance of Saba could be increaced by more regional levies in that region(if possible even a elite unit). If i look at the recruitment viewer that region is either red or not colored at all! there is just nothing that would motivate you to expand down there, other than conquering the whole world :( there has to be SOMETHING that could increace the popularity of that region.