Ill throw in a shocker, I agree with you Bill, Brunei in the early days (pre-Spanish to early Spanish invasion) held great sway over PI. Though, I would temper that statement while they had great influence (I believe if I remember correctly the Sultans of Sulu and the Sultan of Tondo, which soon becomes the city of Manila, were both directly and closely, eg. one relative apart vs the general inter-relation among Malay royalty,related to the Sultan of Brunei), they were not in complete direct control.
Of course this relationship changes over time.