There are plenty of counter picks to both of those characters. Ironically, Galilea is a great counterpick to Ambra with the stunted healing helix. Neither character is unmanageable. I have no issues on Montana dropping Galilea with a knockup and sustained damage.
Look, certain characters need to be focused. That’s the nature of these games. As a team you need to coordinate group fight priority. Ambra is high group fight priority just like Miko because she can effectively keep her team going. Galilea is up there with an AoE focused on herself. But she is more manageable for certain teams, so team composition comes into play. Neither character needs a nerf, certain players need to be better, haha. Oh, not directed at you as I don’t know how good at playing you are.