Oh yeah, plenty of my destroyers and battleships have died to ironclads. I do one of two things, either not attack, they do better defending (all sea units seem to) or I bomb them to 1 or 2 hp before I attack. I've also had transports destroy battleships too, which is a joke.
They do seem to be consistant, I'll lose not 1 out of a hunded modern armors to calvary, but 2 out of 5. I't could be the stats we see aren't the real stats, and they were changed at some point. I did notice the manual is filled with different numbers than the ones seen in the game menus.