Here's the thing with the dragon -

There are a lot of transpositions. White can mix up g4, h4, 0-0-0, and Kb1 in a variety of ways.

Looking for a "refutation" here is pointless. There isn't one. White's position is fundamentally solid and all he's done is tinker move-orders. What you should play defends on which variation you want to play.

White can elect to omit h4 altogether. 10. ... Ne5 11.Bb3 Qa5 12.0-0-0 (white's not going to get any sort of kindside attack going without this move) Rfc8 13.Kb1 when ...b5! seems like the right move - not with the idea of b4, but rather, with the idea of Nc4, Bxc4, bxc4, switching the attack to the b-file. (If you don't normally play Qa5 and Rfc8, then Rac8 is appropriate, instead, leading to the line you found in MCO).

13. ... b5 and 14.g5 is not scary (Ne8, and where's white's attack?) and neither is Nd5. White's adopted a slowish plan here, so it's not suprising that white is doing fine. See leygue-rausis Creon 1999.

The issue here is that you need to understand the key ideas in the openings you play - particularly in the dragon, for crying out loud - so that you're not thrown by what really amounts to little more than a transposition.

And playing the dragon relying on MCO as your main source ... well, that's just playing russian roulette.