Is it easier for a Japanese person to read Mandarin or Cantonese?

I noticed that the characters in the third person pronoun of Mandarin「他們」exist in Japanese with somewhat similar meanings.  In Japanese 他 means “other, another” while 們 means “fellows, folks”.  The negation particle in Mandarin「不」also exists in Japanese (there it is more of a prefix in nouns is the “un-” in “unhealthy” or “im-” in “impossible”).

By contrast, the third person pronoun in cantonese is「佢哋」。Neither 佢 nor 哋 exist in Japanese.  The negation particle 「唔」is used in an obscure noun meaning “the sound of reading aloud”.  In other words it has nothing to do with negation.  

My conclusion is that it would be easier for a Japanese person to read written Mandarin compared to written Cantonese. It this correct? Note that I'm using traditional Chinese instead of simplified, since traditional is closer to Shinjitai.