The pages originally being his and that he might have a good motivation doesn't change that the orc has played a antagonistic role* in relation to Snout so far.
Maybe that will change, maybe not, we'll see.
Would be funny if Arudak followed Snout because he noticed the poor guy wanted the book too and tried to give it to him.
*Mind you, antagonist, not villain or bad guy. If the story's about the Evil Overlord conquering all of creation he's both the villain/bad guy and the Protagonist and the ragtag bunch of misfits trying to stop him might be the heroes, but they're also the antagonists.