In a way, the question could almost be reversed.... Listening to The Beatles from the White Album onwards, a large part of the sound was very McCartney-ish; obviously, as those songs were all written by him! However, that seems to have been the style and sound for which he was striving, so it's only natural that many of the songs off his first couple of solo LP's would have had that 'feel' too; with the only real differences being that J, G, and R, weren't playing too!
Paul had been doing the 'whimsy' songs since Pepper, and were almost 'unique' to him; no-one else in the Beatles wrote that style, so it has naturally become a sort of trademark sound for him. We know that at least one song; 'Junk' was written and demo'd during the White Album period (a song which I adore), and would, in my opinion, have fitted on to that album perfectly. That he saved, and refined it for later use on the 'McCartney' LP indicates that his style hadn't changed too far beyond that of 1968 yet.
I think that by 'Ram', he was evolving newwer directions, but the overall sound is still very much what we'd become used to over the later Beatles albums, and 'Ram' is no worse for that! I love it! I think that most of the songs from it compare favourably with, and exceed many of his Beatles songs, especially those from the White Album, although there are fair-few gems there too!
Overall, I think that both 'McCartney' and 'Ram' are comparable to, certainly, the last few Beatles LP's.