Personally, I'd be ok with the 12:35 arrival if there is a later flight in case of trouble. I'd check the limobus times from HND to NRT first, though. Even the 11-ish arrival lets you have a leisurely morning before catching your flight and still leaves a fall-back flight in the rare case that the 11 departure is delayed or canceled. Being a belt-and-suspenders kind of guy, I never like to rely on the last possible flight to make an international connection. YMMV.