Diocletian was asking, on TMP, how the various larger Late Roman ranges compare.
First I should apologise for a little distortion in the photo; on the table, all the figures were lined up with the bottom of their bases parallel. Also I don't have any of the Crusader http://www.crusaderminiatures.com/list.php?cat=13&sub=29&page=1 Late Roman figures, yet, which I would certainly want to look at, if I was considering building a Late Roman army in the near future.
There is clearly quite a wide variation in figure height. The Gripping Beast Range http://www.grippingbeast.com/shop.php is the tallest, perhaps 4mm taller than the Foundry http://www.wargamesfoundry.com/main.asp . Black Tree http://www.blacktreedesign.com/home.html are interesting, because there is some variation in the height of the range; the middle figure is at least a millimetre taller than the 4th figure along, and more heavily built. I briefly wondered whether it was from GB and had got into the wrong bag. On the other hand, the 4th figure from BTD is only around 3mm taller than the Foundry on the right and feels to me like it would work with the Foundry range (as Allen showed in his heritage photos of Dave Imrie's units, where Foundry and BTD are successfully mixed).
My personal feeling is that whilst I'd mix most (but not all) BTD minis with Foundry, and certainly mix BTD and GB, I certainly wouldn't mix GB and Foundry. And the BTD horses, of course, are pretty ghastly...