Ebbie, I hate to tell ya this, but you blew the calculation. The long, long, livers don't add up end to end. The age at which Muthoosala begattified the next in line is given, as with each one in the series. That doesn't begin to make the whole narrative realistically possible, but: if you were to put your theory to a young-earther, he would show you up as one of them there ignorant old-earth people right there on the spot.

Incidentally, I think it adds up so that old Emmy, the longest liver of all, died in the year of the flood. Was he less than saintly, and therefore left to drown?