title_body: Contradicting sayings about the order of drinking alcoholic beverages
upvoted_answer: According to this link, different types of alcohol have differing amounts and different types of congeners (which are one of the primary toxins contributing to a hangover) in them, leading to varying degrees of hangovers. Combining these varying toxins in different ways can lead to different results. Red wine apparently has the highest amount of congeners in it, while clearer liquids tend to have have fewer. 
  
  Another thing noted by this article is that carbonated alcoholic beverages (e.g., beer) cause the body to absorb alcohol more quickly; therefore, if you were to consume beer before liquor, your body would have even less time to deal with the alcohol absorption than the other way around. 
  
  Other than your reasoning as to the amount of alcohol content drinks contain, this is the only thing I can think of!