Having just watched the LotR film trilogy yet again, I've undergone an epiphany regarding how I wrote goblinoids in Engines & Empires. In that book, I set up most of the single Hit Die gobliny types (kobolds, goblins, orcs, hobgogblins) as various tribes of Tolkienesque Orcs, leaving bugbears (with their 3+1 HD) to stand in for the Uruk-Hai.
(The exception would be kobolds, which I re-dubbed "imps" in the E&E book as an homage to the badly transrated Engrish of Final Fantasy I, where the bakemono, a.k.a. goblins, are called "imps" to save character space. Four syllables in Japanese meant room for only four English letters when the game was localized! Ah, well, if you look very closely at E&E, you'll see that most of it is actually an attempt to synthesize Final Fantasy and Tolkien. In fact, I'm pretty obvious about it in places.)
When you think about it, the Orc/Uruk divide makes sense enough, if one is trying to emulate a Tolkien-inspired feel for goblinoids. Tolkien himself described many tribes of Orcs, generally hostile to each other, with northern Orcs from around Gundabad and such being larger and tougher; Orcs from the Misty Mountains region being shorter and weaker; and Mordor Orcs being swarthier, smarter, and more quarrelsome than others. And while Gundabad and Mordor Orcs were the strongest of the lot, they still weren't any kind of match for Saruman's Fighting Uruk-Hai. So there's some justification for using lots of different sets of stats for Orcish "sub-races" and then using bugbear stats for Uruk-Hai.
But as I was watching these movies, it occurred to me that the Uruks weren't that much tougher than plain-old Orcs. In fact, the disparity (as they're portrayed in the films) is little different than a simple matter of height, as between Men and Dwarves. According to that logic, Uruks ought to be no tougher than D&D's hobgoblins. It also occurred to me, around this time, that I had completely neglected half-orcs (which, in Tolkien, are a far cry from D&D's musclebound barbarians—rather, they're very thief-like spies, thugs, and ruffians; and so, to me, it's no wonder that in AD&D 1e, the half-orc favored the assassin class above all others!).
So, if I were to re-scale the goblinoids for use with (for example) a six-level steampunk campaign, I would probably shift things down a bit. Something like this:
Hit Dice ... D&D Monster ... Equivalent For My Home Game
1/2 ..... Kobold .................... Imp
1-1 ..... Goblin ..................... Half-Orc
1 .......... Orc ......................... Orc
1+1 ..... Hobgoblin .............. Uruk-Hai
2 ......... Gnoll ....................... Beastman
2+1 ..... Lizardman ............. Lizardman
3 .......... Thoul ..................... Grendel
3+1 ...... Bugbear ................ Ogre/Bogeyman
4+1 ...... Ogre ...................... Troll
6+3 ..... Troll ....................... Olog-Hai
Imps: Small, mischievous goblinoids which tend to inhabit forests and mineshafts. They often do the bidding of evil magicians.
Half-Orcs: A mongrel race of blended orcish and human blood, created through foul sorcery. Half-orcs aren't particularly tough, but they have orcish wickedness in their hearts and a limited ability to blend in with humans. They tend to be thieves, thugs, and hired killers. Basically, D&D goblin stats, minus the daylight penalties.
Orcs: Your run-of-the-mill goblinoids, foot-soldiers in the armies of Evil (Inc.) and eternal servants to the Dark Overlord of the Month.
Uruk-Hai: Although I name them "Hulks" in my campaign setting as an offbeat reference to another fantasy author, they're basically what it says on the tin. Upright-walking orc-kind created by breeding half-orcs back with regular orcs, to create a race of mannish orc capable of using large weapons and withstanding sunlight. For the purposes of this ruleset, it's just a matter of using the hobgoblin stats as-written (by the original RAW, they already have no penalty for fighting in daylight).
Beastmen: I always thought that gnolls were kind of an out-of-place monster, but a generic race of beastmen is very pulp fantasy, in a He-Man sort of way. I would probably wind up using these like Robert Jordan's Trollocs. (Lizardmen, on the other hand, always seem to fit in nicely, even if they're basically Sleestaks.)
Grendel: I don't know why, but I've always identified the thoul with the nasty trollspawned monster from Beowulf. Make of that what you will.
Ogre: Now this is where things start to get interesting. "Bugbears," like gnolls, are another one of those monsters that just seems like a mythological misfit... unless you're trying to use it in the traditional sense of the Bogeyman of English folklore, in which case, sure, I can see them as oversized goblins. But hairy almost-ogres haunting dungeons? Might as well just call these guys "ogres" and use them in the Shrek sense. Ogres and Bogeymen are of the same ilk, too: big scary monsters that you scar your children with by telling them gruesome fairy tales about how the big nasty Ogre will eat them if they don't behave. So, yes, it seems convoluted, but I think I'm going to start using the bugbear stats for ogres.
Troll: Now trolls are a weird concept in mythology, because sometimes they're dwarfish and sometimes they're gigantic. Are they rubbery and regenerative and prone to flee from fire like Frankenstein's monster on 'shrooms? Or are they big and hulking and made of rock and prone to petrifying in sunlight? I'm going to go with the petrifying variety, not least because of Tolkien, Norse mythology, and the fact that I watched David the Gnome when I was little. So just take the ogre stats, add "petrifies in sunlight" as a weakness, and boom, you have Norse trolls. (Or "rock trolls," maybe.)
Olog-Hai: Sauron created these "great trolls of Mordor" which aren't petrified by sunlight, to do battle for him in the War of the Ring. Now these are fearsome beasts worthy of the proper D&D troll stats! 6+3 hit dice, and regeneration when the wound isn't from fire or acid? Heck yeah. All I really need is a catchy name for the great trolls that isn't obviously taken from another source. I'm thinking "Orgg" (yes, after the ubiquitous 6/6 red critter from M:TG). At least it sounds rather like "Olog".
Skeleton (1 HD)
Zombie (2 HD)
Ghoul (2 HD)
Wight (3 HD)
Wraith (4 HD)
Mummy (5+1 HD)
Spectre (6 HD)
Vampire (7—9 HD)
What you see above is the list of standard low-to-mid level undead (everything in the Basic / Expert rules), stuff that can still be turned by a cleric below 15th level. In a six-level campaign, a vampire is definitely the toughest undead one might ever want to throw at a PC party, too. So I like how this scales. I would only make two minor changes to this classic family of critters.
1) Ghouls. Ghouls are a positive pain in the arse as written. Three attacks per round, plus a paralysis save to be rolled every time they hit? Using a couple of ghouls creates a storm of dice-rolling to muck up the combat. I would much rather distinguish them from zombies by giving them 2+1 HD (so that they attack as 3 HD monsters) and then balance this out by shortening their attack routine to claw 1d4/claw 1d4.
2) Vampires. I'm not quite sure how, mechanically, I want to model this, but I like the idea of using 7-HD vampires as the low-ranking or young vampires; 8-HD for varcolac (elder vampires with a wolfish affinity), and 9-HD for nosferatu (powerful vampire lords with a decidedly batty physiognomy). Perhaps the garden-variety vampire doesn't cast spells, the varcolac casts spells as an 8th level cleric/druid, and the nosferatu casts spells as a 9th level magic-user.
Time for a Farscape quote.
Aeryn: Look, this is hardly the time for human nonsense, Crichton.
Crichton: Oh, god, that is it—you are so damn smart. There's no time for stupid human anything. And I'm sick of it, Aeryn. I'm sick of Napoleon XVI. I'm sick of Blue. I'm sick of Tentacle Boy. And guess what? I'm sick of you. I'm sick of this whole turd-burp end of the universe.
—Episode 1.14, "Jeremiah Crichton"