Base Guy slapped away Gaara's Sand Coffin, whereas Kimimaro could not, and even needed CS1 and bone masks under his skin just to survive. Now you can argue that Gaara at that point was stronger than he was in the Chunin exams, but the gap between the two clearly could not be that wide if Kimimaro was dodging his sand attacks in base, while being around "fresh out of the hospital" base Lee's speed level. Add in the other crazy stuff Guy has done in base (knocking away a physical powerhouse like Kisame, his feats against Obito), and you could make a good argument for Guy against base and even CS1 Kimimaro.
Now add in the boost that the 6th Gate gives him, and the fact that Guy evaporated a tidal wave and countered an acid mist from a Bijuu with Asa Kujaku, and Guy stomps. Even if I were to assume that Kimimaro can survive the heat of Asa Kujaku in CS2, he is definitely not staying in CS2 longer than Guy can stay in the lower Gates (3-5), considering that he doesn't need to be in the 6th Gate to avoid Kimi's attacks.
Therefore either Kimi gets stomped before he can reach CS2, he gets stomped in CS2, or if you really believe in his durability, Guy dances around him while he's in CS2, then stomps him after he cancels the mode due to exhaustion.
Now add in the boost that the 6th Gate gives him, and the fact that Guy evaporated a tidal wave and countered an acid mist from a Bijuu with Asa Kujaku, and Guy stomps. Even if I were to assume that Kimimaro can survive the heat of Asa Kujaku in CS2, he is definitely not staying in CS2 longer than Guy can stay in the lower Gates (3-5), considering that he doesn't need to be in the 6th Gate to avoid Kimi's attacks.
Therefore either Kimi gets stomped before he can reach CS2, he gets stomped in CS2, or if you really believe in his durability, Guy dances around him while he's in CS2, then stomps him after he cancels the mode due to exhaustion.