This is a big misconception. Mistwalker didn't "make" Blue Dragon or Lost Odyssey. They are a very small team who assumed the role of producer for these two games (and Last Story). Mistwalker is a very small studio composed of Sakaguchi's colleagues, but they never made a AAA game on their own.
Blue Dragon was made by Artoon(the studio behind Blinx) with Sakaguchi serving as the writer and Uematsu as the composer. Artoon's Takuya Matsumoto served as the director. After Artoon was absorbed into AQ Interactive, key members like Yoji Ishii and Naoto Ohshima formed Arzaest with many of the former Artoon devs.
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Lost Odyssey was originally an internal project by Microsoft Game Studios(the studio which made Phantom Dust and was later dissolved, and the the devs led by Yukio Futatsugi formed
Grounding Inc.) with Mistwalker led by Daisuke Fukugawa(Director of
Magatama for OG Xbox). Development continued with the new studio feelplus with Daisuke Fukugawa remaining as the director again with Sakaguchi serving as the writer and Uematsu as the composer.
Game credits, biography, portraits and other game industry information for Daisuke Fukugawa - MobyGames
www.mobygames.com
en.wikipedia.org