The fall of Arche Seleukeia- a question about AI faction progression in 1.2

[Stelios]

I'm about 70 years into my 1.2 M/M Romani game, and i've been observing a phenomenon i've never seen in any other EB game. Until recently, i've played on versions .80, 1.0, and 1.1, and i'd say eight times out of ten the seleukid empire domniates the eastern map. The other two times the Ptolemaioi would triumph and begin eating away at the Seleukids, pushing east but usually not getting past Babylon. For the first time, I've witnessed Baktria, Pahlava, and to a lesser extent, Hayasdan, swallow up the eastern stretches of the Seleukid empire. I would post a map if i knew how to do screenshots, and i may in the future, but to get an idea of what i'm describing, Baktria and Pahlava have split the AS north and south almost perfectly, with Baktria getting the south and Pahlava getting the north. Hayasdan has actually taken advantage of this and pushed south, which led to these three "breakaway" factions uniting around Babylon. Pontus has also cut off the last few AS territories in Turkey by holding eastern Anatolia, and Egypt swallowed up everything that was left. This is only my second real game of EB 1.2, and i'm amazed (and pleased) that the Arche Seleukeia has actually broken up the way it was supposed to. Is this mere chance, or was something corrected in EB 1.2 so that the "breakaway" factions actually aggressively attack Arche Seleukeia? Has anyone else seen this happen before, and on what version of the game? I apologise for the lengthy background for this question, but until i can post maps, i'm somewhat limited to descriptions.