No Owain Glyndwr was greater than Churchill, if I remember right Glyndwr beat Churchill (and Abraham Lincoln) in the most influential person of the millennium poll, I don't think Churchill even came in the top 20, Glyndwr was definitely top 10, it was voted by top World leaders, scientists, artists, etc and not the public.
Don't believe the English hype around Churchill, the English always big theirs up out of all proportion.