And also do not forget that people used to be smaller than are now just look at armors in museums though northern people were for long time known to be taller than Mediterraneans for example in Ancient and Medieval times.
I am more-less kidding of course when looking on topic but it is true as a fact (and also it is always tempting for me to search for other than obvious answer).
I would like to know whether besides game mechanic difference alteration of size could change performance too because as for me I would prefer rather no pushing performance more.