Formation Monsters with same Skill

Firstly, already aware they dont double up (ie 2 monsters with imp down dont double up) my issue isnt with this it's something else.

One irritating thing I have found is either the speed or position of a monster will determine which skill is cast first when there is a double up.

I have Quetz and Vritra in my team, both with imp down.

I've been levelling vritra's imp down and watched a battle to see how it went... vritra's imp down was never cast.

Instead Quetz's lowly +1 imp down was always cast first.

I'm yet to determine if this is cause Quetz is my party leader or has a higher speed than Vit (higher BP value so possibly higher speed??), anyone know the answer to this?

If it's a speed thing then this sucks as it means Vit's higher imp down will never be cast (it's only 5 atm but still...).

I guess a warning for others if in a similar position!

Actually, i think position in the party is on the right track. from looking at my regular formation, skills are cast in a top down manner. first the leader, then the monster to the left(or above the leader in a fight), then the monster to the right(or below leader in a fight), then the monster to the left of the second, then the monster to the right of the third.

one other thing. there're two skills that DO double up, but then they don't affect the whole party, just the monster that uses them. i am talking about crit up and dodge. those do double up, from what i've seen.