second paragraphA specific under dark breed of orcs.The wiki page for orcs.Uruk-Hai being a breed of smarter orcs. Not to say that all orcs are this vicious or cunning, but that they exist. They weren't created with magic so much as selective breeding practices(I read up on this one as well.). You're using pretty exclusively bad examples to say this is the norm, as we've established there are dumb orcs. There are people dumber than orcs too, but a -2 to mental stats doesn't make you retarded. It just means they're not going to make giant innovations like Einstein would.
However lets cling to stats and compare an orc mage to a human mage for a moment.
18 int for human.
16 for orc.
By 20th level the human has an intelligence of 34. (1-20 level progression so 4th8th12th16th20th go to int, +5 stat buff tome + 6 item for a grand total of +16 to 18 = 34. The same goes for the orc.)
The orc has an intelligence of 32.
Who wins this aimless pissing match? I haven't the bleeding foggiest, it all comes down to the person at that point. Two points isn't enough to really make a huge difference long term. We're generally looking at a 5% difference. Orcs are 5% dumber than humans. Whoopity ******** doo. My point is clinging to the stats as an argument is plain narrow minded(I.M.O.). They're a guideline for how to RP.
What frustrates me about your post is that it seems to have missed a majority of the point; and furthermore it only regurgitates information that has all ready been established and agreed on (Not the chainmail post. That's really, really obscure material from way back in the day to my knowledge(could be wwwaaaaay off on that.)). We're not debating the majority or the established guide lines but the statistical outliers of possibility. As those seem to be the interesting stories we want to hear about. It's why baseball is boring until a dove gets hit by a pitch (It fricking exploded.). It's why we celebrate the outlandishly good and bad. George Bush at the very least is going to be impossible to forget. We still need flaws that we as people can relate to, it's what allows us to vicariously live through them as well. At the least to my knowledge that is the modern theorem on making characters relate-able is people we can emotionally connect with in extraordinary circumstances. It's why goofy Wash catching a giant spear to the chest was so god awfully wrenching. It also made us unsure of the out come because Joss Whedon was flying in the face of standard Hollywood movie convention. God love him for it too.
I'll get off my soap box now as ranting on like this is more than a bit of a d**k a move. I still however feel that voicing my opinion on the matter is also important. As I've said this isn't so much as invalidating your point (as it even agrees.), but to illustrate that I if not 'we' (as ostentatious as that is, please forgive me. Especially if I'm way off.) think you've missed the point. We're talking about the outside realm of possible. I'm talking about in this instance that if it's well executed it is a really really good story we're all very glad to see.
I'm also snowed in with a nasty tooth ache. I literally have ******** else to do.