I wouldn't worry about size comparisons - even more than humans, broo can vary size-wise (and everything else-wise). I use broo & beastmen minis from a wide variety of manufacturers - it gives a nice "random" feel when you've got little Trollkin Forge/Citadel broo next to big Grenadier minotaurs, with Ral Partha, Lance & laser and Martian Minis inbetween. I usually stat out the bigger guys as more powerful. Usually...
