It's easy to tell by looking at it that vodka is not beer. In fact you can often tell how alcoholic a beverage is just by sniffing it. Is the same true for different intensities of cannabis? In any case, hard liquor is certainly far more dangerous than beer (when you hear about college kids who died of alcohol poisoning, it's always from liquor - the physical limits of the stomach generally prevent you from getting worse than a night of vomiting and a hangover from beer). So I'm not sure that the analogy to alcohol is helpful to cannabis.