Grazul can be a good secondary healer for wars or when you need to stack red. Time her special right and she can protect you from ailments too. She probably will not get Cleric emblems over Ariel though as I would prefer Ariel’s bigger heal myself.
JF can spread damage across the enemy team quickly, and it gets better with emblems. He pairs well in most 3-2 stacks due to that, any sniper greatly enjoys having their target brought down to KO range. The Ice defense buff and the defense flip are both built to counter Finley.
Both JF and Grazul are pretty different, so pick whoever you think fits your needs better. I personally prefer JF myself.