its not so much about the meteor being smart, its about the spreading of the impact. think of it like a bed of nails, if there is just one nail on a board and you try to lay on it, it will penetrate (all damage on one creature). if you put two nails an inch apart, they may still go in, but not as deep (still big damage to two creatures). (continue the trend)... if you place many nails over the same surface and lay on it, it will give you a few discomforting pricks (low damage to many creatures).
That might work with nails but this is a freaking meteor we are talking about here.
Just like the amount of people living in a city does not affect the effectiveness of an atomic bomb, I don't think damage done by a meteor is affected by how many creatures are crushed beneath it. Creatures somehow "blocking" the meteor just sounds weird to me. This card can could kill 4 creatures with 5HP, but when you add the 5th creature, nobody dies. So basically that 5th creature somehow body-blocks the damage done by the Meteor.
The mechanics you are using now sounds more like "Chain Lightning" or something, where the spell has a specific amount of "power", and that power (damage) is divided between all creatures. That makes sense to me. Body-blocking meteors.. not so much.
To me AoE using spells is about one thing:
how to target your spell so that you can maximize the damage done to your opponents. If they ball up, you throw in a Fireball, they all die, and you are happy. Nothing is more awesome in gaming that taking out a bunch of balled up opponents. But here that fun is mostly missing because:
A) You cannot target it
B) Damage is divided, meaning sometimes the more creatures are balled up, the worse it is for you (all die vs. none die example I gave earlier)
But although I disagree with some mechanics, it's still an interesting idea.
