Personally I don't see a RTW being a good choice for only 3 destinations on any alliance unless you are flying C or F ONLY between cities where tickets are incredibly high in general. (TYO, SIN in Asia from major business centers in Europe and US for example). Even then if you learn some creative "tricks" and are not alliance specific then you can game the system and still be well ahead for 3 destinations.

EY, EK, and QR offer a lot of incredible long haul C fares. None are part of my preferred alliance so I personally ignore them, others obviously don't mind.