Read this in a book of short snippets and stories:
President Truman attended the Yalta Conference of the Allies during the Second World War. He found Winston Churchill very difficult, adamant and hard to convince. On the other hand, he found Joseph Stalin of Russia very affable. friendly and easy to convince.
Churchill literally fought before putting his signature on any agreement or amendment. Stalin was ever ready to cooperate and signed agreements without much difficulty.
The Yalta conference was concluded. The arrangements for the implementation of agreements began. then Truman found out the truth. Winston Churchill adhered to all the agreements and implemented them with total sincerity. Joseph Stalin did not care about what was agreed upon and proceeded energetically to implement his own secret agenda. The result of the two approaches is now history.
Then Truman realized that Churchill was being difficult because he had every intention of being committed to the agreements. Stalin was friendly and was ready to agree because he had no intention of fulfilling the commitments.
Happens so often in our day-to-day life. Interesting that I never stopped to frame it this way. The guys who fight before agreeing are generally thinking through what they are agreeing to; others are just giving it air.