A water duo could work. We need to use duos, since we can't really afford a mono at this stage considering we're down to 1 dragon and 5 OEs to spread throughout 4 decks. A few squids can single-highhandedly shut down a large portion of the metagame, and toads are highly efficient attackers.
Here's how I see things. Here are the decks and their costs.
Dim DragOTK - Strong against non-PC decks, very cheap because it only requires 1 Air card, the dragon. Good choice if we're low on Air cards.
Flying OE/Shock Bonewall - Decent deck, but it requires a lot of Air cards. I wouldn't really use this.
Grabbow - Great deck, but semi expensive. Still, it's probably something we should use.
Light Stall - Like the Flying OE Bonewall deck, it's kind of expensive. But it's a pretty good deck too, so we might be able to use it.
Fire Duo - Effective and cheap. Great choice. Almost surely something we should use.
Time Duo - Semi cheap, but not highly effective. We can use this if we have to.
Water Duo - Semi cheap, effective. Likely something to use.