Ah, Orcs of Thar - the book that ended up a badly produced bit of parody.
The attribute adjustments for the Thar races seem a bit different. They are summarized here:
Kobold: -4 Str, +3 Dex. +2 natural armor. d4 HD
Goblin: -3 Str, +1 Dex, +1 Con. +1 natural armor. d8-1 HD
Orc: +1 Str, -1 Dex. +1 natural armor. d8 HD
Hobgoblin: +1 Str, -1 Dex. +1 natural armor. d8+1 HD
Gnoll: +1 Str, -2 Wis, +1 Dex. +1 natural armor. 2d8 HD
Bugbear: +1 Str, -2 Wis, +1 Con. +1 natural armor.3d8+1 HD
Ogre: +2 Str, -1 Wis, -1 Dex, +1 Con. 4d8+1 HD
Troll: +2 Str, -2 Int, -2 Wis, -2 Dex, -2 Cha (ouch!). 6d8+3 HD
* Natural armor taken as 9 - AC listed on p. 15 OoT PG (naked D&D characters are AC 9).
* Starting HD as a level 0 tribesman.
Worth creating separate Mystara subraces, probably not. But there you go
