PSR is a wonderful source for reviews and comparisons of all sorts of 1/72 scale figures. If the size they measure is within 1mm of the other figures you wish to purchase, then they probably will mix well. Many of the figures have a link to PSRs size comparison as well. Not all figures are compared but many are.
"Nearly all men can stand adversity, but if you want to test a man's character, give him power."