Well thought out post, but I have a hard time seeing any similarity between Seattle's DL and our own.
Hatcher is like Bryant? Not even close. Completely different players, and while Bryant is listed at 18 pounds heavier than Hatcher, I'd be stunned if there was less than 25 lbs. separating the two.
Alan Branch is a 325 lb. NT-type playing the 1-tech for them. Who's that guy here? We don't have one. Rat and Lissemore are too light, and Brian Price at 303 lbs. is a bit light and who knows if he can be counted on to contribute.
Even their 3-tech, Brandon Mebane, is 311 lbs. and is significantly bigger than our 3-tech options.
I'm not saying I advocate matching Seattle's size... as a matter of fact I'd much prefer a SDE that can move and rush the passer much better than Red Bryant. My only point is that we literally average about 15 lbs. lighter on average across 3/4 of our DL as it stands now. We're at a serious size and talent deficit.