Re: Who was stronger the Romulans or Klingons?
My estimate is that they were about equal, or the more powerful one would have tried to conquer the other. And I estimate that each were somewhere between 51 - 74 percent of the power of the Federation - which is why whenever the Romulans or the Duras family plot against either the rest of the Klingons or the Federation, they always seem to need one another to do so.
As the brilliant philosopher once said... Everybody, have fun tonight. Everybody, Wang Chung tonight.