Yeah Moubu is the superior general overall.
That being said, we haven't seen him doing anything creative in more complex terrains. I would really like to see how he performs there and I guess the opportunities are gonna come up going forward. Someone like Kanki was in a bad spot in the opposite direction (if all he has is flat land where he can't apply his "bandit style" warfare).
Now, Moubu was still someone who grew up and learned in the military context, furthermore Shouheikun influenced him. He has "a deep understanding of war" according to Ouki. So even in the worst case scenario, that still wouldn't be a Kanki-level of bad problem. And he is a 6GG. But yeah, I look forward to seeing to how he would do on his own.