Reddit mentions of Confucian Moral Self Cultivation

I would have to agree with you. Especially in terms of the nature of the self, there is little argument over the individual self and what that means, even though human nature and the cultivation of the self takes a front row seat in both Mengzi and Xunzi. I would take that as perhaps an indication of how neither of them really thought that was a problem they would have to deal with, rather than something they just ignored (I may be mistaken in thinking talk of self-cultivation implies that a self must exist).

The real conflict between Confucianism and Buddhism comes after Buddhism was integrated into China through the Han and up into the Tang dynasties. At which point Neo-confucianism started to appear as a result, much of which would take Mengzi as their standard. This would give rise to the orthodox Confucianism we can see today, which is based mainly on Zhu Xi and his interpretation of Mengzi.

For anyone looking for a great read on Mengzi that won't take much time, I would recommend this book and if you want to actually read Mengzi, I've been using this tranlsation and commentary. Ivanhoe also goes on to look at Neo-Confucianism, so if anyone is looking to see arguments from Confucianism against Buddhism, that is highly recommended.