jose, i'm pretty sure they're maranao. got a picture of datu pedro and datu mundas, both maranao. i could be mistaken, but the pic you provided is that of datu mundas and his retainers:
if nothing else, the 'do of the boy carrying the spear in your pic is straight up maranao. here's a nice group pic of the the lake moros. notice the buns:
