Kick boxing/Muat Thai is overrated for MMA. Effective kicks aren't easy to land and can be risky, as you give up you base. Low kicks are easier to land, but less effective. They are a weapon of attirition, to slow your opponent down over time.
I have considered western boxing much more effective for MMA for a long time and stil do. Although I encourage fighters to learn how to kick properly, a) so it's in their arsenal and b) because the motion of a good thai dtae gives superb flexibility to the hips which aides ground work and boxing
*to add, I have 8+ years experience of pure Muay Thai, a red kurang ruang and an instructors grade, so I speak from an educated position*