I hope you realize that book amounts to a completely racist propaganda piece from an age where people thought that exterminating all the orsimer was a good idea.
And to iterate Shino, the orsimer are the most intelligent of the fighting races (nord, redguard, orc). Then again, that's mainly due to the female orc having 40 int in the last 2 games, while everyone else had 30.
Yes, it's quite obviously propaganda. I'd still expect the author to get the appearance right, though. Especially since they have upturned noses in previous ES games
. I just get nervous when we see any "The author was wrong" retcons. Remember the "once jungled" Cyrodiil? At least Bethesda appears to be paying attention to lore in TES V, though, so I doubt we will see the retcon cascade of TES IV again. It still stings I bit when I feel the bite of the retcon
axe blunt weapon, however
.
And yes, I also realize they can be quite intelligent. There were quite a handful of orc magic users in Morrowind. I was a little bothered that there weren't any orc magic users in TESIV and few nord magic users.