Anyway I think out of the three kingdoms,Wei(caocao)is the
best,coz he established relationships with northern ethnic
groups.therefore the invasion of wuhu(5 northern namadic groups)
were been delayed.As we know,after Jin dyasty(the dynasty after
3kingdom period),the invasion northern nomads caused the
deaths of 80 percent of Han chinese.If CaoCao didn't unify
the northern Han territory,the invasion of the northern nomads
would be even more earlier and as the Han kingdom is in chaos and
not united,there wouldn't be any effective resistence to the
nomads,so the deaths of Han people would never be just about
80 percent,may be the whole race would be extincted or been forced
to escape from the mainland(such as the Sinhalese,the original
Northern Indian people were been forced to move to the south by the
aryan whites).Or if Cao Cao can unify the 3 kingdoms earlier,the
Jin dynasty would even exist in Chinese history and as the Han
Kingdom is united,the 五胡乱华,the massacres of Han people caused by
the northern nomads wouldn't happen also
I agree with your observation. History never records Chief
Minister CaoCao as evil but a maverick who admired talent.
It is the later generations thru' poetry, stage wayang, song etc
that painted an evil CaoCao.