I would have gone with the Pentastar Alignment. I couldn't have stayed loyal to the Interim Ruling Council or Isard, especially if I was a commander thinking of my troops welfare I couldn't go with the other warlords. Kaine had a stable economy, held the banking center of the galaxy, he was the most powerful Grand Moff, backed by a Grand Admiral, Inquisitor, the five largest businesses, had an SSD, shipyards and did not wage unneeded internecine conflicts with other Imp faction. He would be my obvious choice.