I'll battle the Arcanine first.
I'll ask the Pokemon allying with me if any of them can use a supereffective move on the Arcanine (for all three allies, I'm thinking a combined Rock Tomb will be a nice start, to slow down the Arcanine)...as for my own Pokemon, I'm going to switch Emerald for Sabre, and have him be ready to use Snatch or Mirror Coat incase the Arcanine decides to use a status move that is suspectible to being Snatched or reflected back, otherwise, I want him to use a combination of Feint Attack and Thunder Wave to get behind the Arcanine and be ready to paralyze it, though I don't want him in the path of the combined Rock Tomb if any or all of them hit the Arcanine.
I want to show the two guards here that I'm stronger than even both of them combined.