Here is a quick comparison shot of Front Rank opolchenie and Perry plastic infantry. I'm thinking that I'd have been better off to get the slightly more expensive Foundry opolchenie - the regiment pack I got from FR contains 22 identical figures! I'll see what I can do to mix them up a bit when painting them, but consider that the Foundry ones have more variety for what is, after all, militia.

Still, for my army, they are close enough in size (however note that I have no problem mixing FR, Perry, Old Glory and Warlord in my 1812 army!).