How many Familiars can i catch? And what is the best one?

Little bighorn from old smokey is a good one for Oliver its resistant to melee attacks i have two of them they r kind of hard to catch but worth it you dont need to have 2 though... for Esther always have Drongo on her also gave her Green Buncher from the desert and kept Thumbelemur on her until i got swain in the group then just replaced Thumbelemur with whatever familiar i pick up that is esther's best type and as for swain Thumbelemur should lead completely take out Hurly as he doesn't get a bonus from swain and the last 2 slots i put bonehead the skelly monster from the desert and put anything that went well with swain in the last slot until i could replace it with tin-man a little later on.... i hope this helps