What Arthur says is true (his WWI/interwar Brits are massive, you are right), but there is also something else going on here, and it is a little odd. The oddness is this:
Perry figures aren't as small as we think they are. They somehow
seem small, and in my mind I have them pigeonholed in the "small 28mm" category. But when you actually compare them with other figures they aren't that far below the average, height-wise.
I think there is actually more of a size discrepancy between Copplestone's work for Foundry and his own sailors than there is between his sailors and Perry figures...

But again it is more about bulkiness vs. puniness rather than actual height (though there is a small height difference). All of the above comparisons are within my tolerance range, but of course that is a subjective judgement each gamer needs to make for himself.