In fairness though, he was decent there today (yeah, I know --- Newcastle). In addition, to his assist and dangerous dribbling, he pinned Murphy back nearly the entire match --- dude could hardly get forward like he prefers. I think Martinelli must be a nightmare for many (not all, certainly) defenders to live with --- he never stops moving.
Doubt Arteta would be the one to try it but i really like the idea of a 4-2-2-2 with an attacking 4 of ESR, Saka, Martinelli & Balogun.