Firstly, I would like to denounce Thorongil as a Lord of the Rings heretic. Secondly, my apologies in not specifying earlier, goblin-men, half-orcs and orc-men are different, most likely differing due to male or female of the species used in the crossbreeding (ick) an example would be the tiger-lion crossbreeds. Uruk-hai according to my research, were generally referred to as orcs in that they were, Ugluk and his lot were goblin-men (or the other two kinds) but they were also Uruk-hai, The word means "Orc folk" it was a name given to the professional soldier as it were. the lesser wimpier orcs of mordor and Isengard were generally referred to as snaga (slaves) they were generally assigned the duties befitting that of slaves as well as fighting when the need called for it (i.e. The Battle at the Black Gate) and since Sauron attacked Minas Tirith sooner than he intended, it is right to assume he wanted more Uruks in his army but had to substitute lesser orcs for the better trained ones.
Not quite sure what you're saying at first, but for the sake of it I'll just say that Goblin is used interchangably with Orc - as said in Tolkien's Letters. So anywhere it says Orc you can replace it with Goblin and it will mean the same. Uruk-hai, while having a literal translation of Orc [Folk] in the Black Speech, was used to describe the larger variety of Orcs to the Rohirrim or Gondorians, along with Black Uruks, or the shorter name Uruk. Ugluk, for example, was an Uruk. These Orc-Men, Goblin-Men, or Half-Orcs (all 3 are used interchangably as stated in Morgoth's Ring) were of Saruman's device, and those are what he bred - combining either normal Orcs or Uruk-hai with Dunlendings (or so it is generally inferred). The word snaga was only referenced to once IIRC, so to say that the smaller, generic orcs of Mordor/Isengard/Moria were mostly called Snaga is a bit misleading.
Really, the problem is with the literal translations that Tolkien uses - sometimes I get the feeling even he got confused (which sometimes, especially with regards to Hobgoblins, he did!). But as used by Men who spoke the Common Tongue, and didn't follow the direct translations, basically...
Uruk, Uruk-hai, Black Uruk = Larger variety of Orcs, all Mordor's in origin. Still no match for a man.
Orc, Goblin = Normal Orcs ala Mordor/Moria (etc). All Mordor's in origin.
Half-Orc, Orc-Man, Goblin-Man = What Saruman bred. Not much is known about them, but probably crossbred Orcs with Dunlendings.
I could go into the semantics, but that would become very confusing, not least for me. Almost all those words boil down in the translation to 'Orc', so mostly it is pretty trivial arguing over what each term in the common tongue means, and we should stick to what it is actually used to reference to.
Interestingly enough, the other day I made a short essay on the numbers that Sauron (and Harad) brought to the Pelennor. Came to around 45,000 Orcs and 15,000 Uruks. If you want I'll put it up here in all the detail.
Well nothing can be better than the Dwarven armour, with the exception of Noldorin Armour (those secrets now lost to the elves of course), however the Uruks armour wasn't weak, it was pretty well made, Saruman after all was a student of Aule, he had a "mind of metal and wheels" it was his craft and weaponry that drove Sauron out of Dol Guldur, the half-orcs etc.
See above for the half-orcs, but Saruman, while a student of Aule, was never given any particular mention about his skill of making armour - indeed, although he was said to be skillfull with his hands, the only thing he was said to make was a Ring in imitation of the Rings of Power, and as far as we know, it had no power, or very little.
were described as being man-high with thick straight legs, the orcs had bow-legs, the Wild-men were at least six foot tall, and the dozen orcs that attacked Eomer when Gimli saved him were more than likely bow-legged, meaning they were only slightly higher than Gimli. Have you ever wielded an axe? It's not easy swinging two-and-a-half feet above your head to decapitate someone. Gimli said the "hillmen were over large for me" not over strong. Also there were about eighty in Ugluk's group of half-orcs, at least twenty, most likely two dozen orcs were slain by Boromir, only four of those were half-orcs, and if Boromir the greatest warrior of Gondor could only slay four.... what do you think would happen to a Rohan Peasant with hardly any combat training?
From the over large comment you can also quite easily infer they were simply too strong. Regardless, height is a great asset, and if Uruks are significantly shorter than Men (which they are), they are already at an immediate disadvantage. I've not ever wielded an axe, no, and indeed it isn't easy, as Aragorn once remarked. I can't find any mention of there being 4 Half-Orcs killed by Boromir, only that at least 20 Orcs (or a variety thereof) laid round him. But if there were 4, it proves absolutely nothing. For a start, it's perfectly possible for there to have only being 4 - he can only kill what's infront of him. Saying he 'only' killed 4 when we have no idea of their original number, or of what point they joined the fray (such as after he was already shot or while he was attacking other enemies) is completely arbitrary and gives no relevant information to
any argument. Again, though, Ugluk was an Uruk-hai, not a half-orc. While I took your joke about Thorongil well at first, if you are willing to persist with the notion about Half-Orcs and the like, you need to read his essay (which I proof read for him at the time, and do completely agree with).
Still, all variety of Orcs are not a match for any man at arms. While a peasant may be a different story, if they have some notion of how to wield a blade and/or shield (which they should, being conscripts) their strength should see them through.