I’m not sure about the rules.
Of the allowed do all: take all their sheep, wall their resources and kill all the boars and deers.
Other than that, you need to understand that 2v1 is a sure loss in the late game.
You need to kill them fast.
Therefore early aggression is key.
I would say standard archer or scout opening would be good enough and try to keep pressure on both, but specially on the 1300.
When you go to castle kill him first.
There is a video by Hera in which he takes down 7 human opponents at the same time (!!).
That’s essentially what he did.