This is an analysis I have thought about for quite a while now. This text also appear in V. Analysis of the Black Speech.
The words uruk, olog and oghor are all attested with the ending –hai. The word uruk means “orc”, oghor-hai are the drúedain or the Wood people – could be Black Speech but more probably Orcish. Olog is pure Black Speech and seems to mean “troll“.
The interoperation of these words seem to be quite straight forward but I have an idea for a deeper and more constructive analysis. These words are a bit odd. Most attested Black Speech words are monosyllabic except from compounds and words with suffixes. And there are only a few words with initial vowel – except these three only ash (one), agh (and) the monosyllabic preposition u from the orc curse and a few names: Azog, Orcobal, Othrod, Ufthak and Uglúk.
In Hurrian (and other ancient languages such as proto-indoeuropean) words can be derived by duplication of syllables or vowels. So my proposition is that these are derived words with a prefix that duplicates the stem vowel. This analysis gives us three new stems and a new rule for deriving new words. The rule is that words for races can be derived from stems by dublicate the stam vowel and attach it in front of the stem. The only problem here is that I had a vision that Zhâburi B should only use suffixes (a rule inspired from Hurrian). The stems are: RUK, LOG– and GHOR-.
The first of these is actually attested in Primitive Elvish. H. K. Fauskanger writes: “ruk- one of the “ancient forms” of the stem RUKU, that yielded the word Orch (Orc) in Sindarin. Other forms include rauk-, uruk-, urk(u), runk-, rukut/s; also the “strengthened stem”gruk- and the “elaborated” guruk-, ñguruk (the latter by combination with a distinct stem NGUR “horror”, WJ:415). None of these derivatives are clearly glossed, though urku (or uruku) is said to have yielded Quenya urko, vague in meaning in the lore of the Blessed Realm (“bogey”), but later recognized as a cognate of Sindarin Orch. The adjective urkâ is said to mean “horrible”(WJ:389-90).” In Elvish this stem has something to do with fear which it does not have to have in Zhâburi. I have not decided what the RUK-stem meaning should be.
The stem GHOR could something to do with with trees, wood and forest so oghor would be the “forest person” and oghor-hai “those of the wood men” ore something like that. Or more probably it comes from the druedains own word for themselves, drughu.
The Trolls were the Shadows answer to Ents and made of stone so LOG could very well have to do with stone or rock.