All criminal codes have always had some degree of what would seem "rational imbalances" because as new offenses are created, the penalties are often set based on the then existing atitudes rather than a "holistic" assessment of how the danger and seriousness of that offense relates to the rest of the offenses. Also, existing offenses (drugs being the seminal example) are sometimes singled out for increases in punishment without regard to hw the new punishments relate to other offenses of greater, similar or lesser "objective" harm.

  In theory,  sentencing commissions empowered to establish universally applicable sentencing guidelines could undertake the rational and holistic revision of punishment provisions and be a strong positive force. But, at least at the federal level, and in some states, the ability, even where the will might be present, is constrained by statutes mandating minimum sentences for some offenses that must be incorporated into the operation of any guidelines.