No way! Everyone dual wields. I was happy to see Maximize was making his NPC different. I say he should stick to Single Weapon Style.
That is exactly one of the reasons I was going for the single weapon thing. Most warrior or thief NPC mods dual-wield. Yoshimo uses single weapon, and Arc has always admired him and wanted to be like him. That is another reason I considered katana instead of scimitar.
I would personally prefer something like: Scimitar, short sword, short bow, single weapon.