First off, I downloaded BC 2.4 yesterday, and already it is the best Total War experience I have had in several years. Truly amazing. I certainly don't need any patches to continue enjoying it. I have a particular preference for playing the Indian factions, and unfortunately these don't have their own accents, but I can live with that.
I've read the previous threads on voices, and I realise voices are a very low priority for the BC team. The factions are divided into 3 accents: the Arabic one for all Muslim factions, the French one for the KoJ, and the Mediterranean accent for all the rest. This cannot really be fixed without a substantial voice submod. However there are three factions whose voice can be very easily fixed: the Mongols and the Kara-Khitan should surely both have the Mongolian accent, rather than the Mediterranean one. And is it possible to give the Vladimirs the vanilla East European accent?
Speaking for myself, I'd probably prefer that the Georgians and Armenians had an Eastern European accent than the generic Mediterranean one, since this would at least differentiate them from their neighbours. And finally, the Indians currently have the Mediterranean accent. Again, speaking for myself, this is obviously as ridiculous as it is unavoidable. I would personally download a submod that changed them to the 'Aztec' accent however, since at least they would be exotic and polytheistic.