I think Kishi tried to balance them out in their ability. That makes it hard for me to put them in an order. When it comes to destructive strength and the best chance to win a battle, it always depends on where who is and who they are fighting. Together they should be unbeatable but seeing their trouble with Madara makes me sad. Madara alone without upgrades would be doable I think. Would be unfair for him though.
I`d say the order would be Oonoki, Mei, Gaara, A, Tsunade. I`m ignoring Tsunade`s importance for the battle here. She is keeping everyone alive and is fighting at the same time which makes me respect her alot but that wasn`t the question of the thread.
They ALL impress the hell out of me.