So how much dark malt is too much?

So my recent stouts have both turned out pretty harsh. My guess is that I've been pushing the envelope on the dark malt front. Here are the recipes for my last two stouts:

Old Dirty Bastard Imperial Oatmeal Stout
Dark Horse Imperial Stout

Now, I haven't consulted Ray Daniels yet (which is next on my list), but I'm thinking that the harshness is because I pushed the envelope too far. Too much roasted barley, too much chocolate, too much coffee malt. What's your opinion? And do you think that they'll mellow out with bottle age? They're not bad by any stretch...just much more harsh than I like my stouts---even the imperial variety.

More than a pound, total, of dark malts is pushing it. You have almost three pounds in one and four in the other.

Fortunately, they will mellow, might take 6-8 months.