Yes, it was quite a generalised question... perhaps I could rephrase it and make it even more general...
Has anyone understood the Dhamma better than the Buddha?
Metta,
Retro.
Well, there is only so much Dhamma, isn't there? I think the Buddha would tell you that many, many understood the Dhamma as well as he did, and practiced the Dhamma to the end just as well as he did. What he is recorded to have said (see MN 108) is that the only difference between him and any other arahant, is that he was just the one who discovered the path, who originated the path, who proclaimed and made known the path, and they are followers in the path.