The way i have my merits right now is

Group 1:
Killer Effects 5/5
Call Beast 5/5

I have killer effects meritted cause i got a Tatami Shield and call beast because jug pets are like supreme now.

Group 2:
Feral Howl 5/5
Beast Affinity 5/5

I have BA merits cause i don't know when the pets will cap, so just in case i have them, and I have feral howl cause i like having a stun-like ability (terror) even though it doesn't work on anything in abyssea. (to my experience) It was good for soloing magic casting mobs.

I know my merits could prolly be set up better but I really don't feel like reallocating them.