Orkz will get into CC the same way that they do in the TT, sheer numbers. A marine unit of 10 will be facing 3 - 4 times it's number in Ork boyz, you may wipe half of them out with range weapons before the close the gap but there will be enough left to engage in melee.

things you did wrong:
1. didn't take armor save into account
2. didn't take leadership into account

and you know the biggest mistake of all?

using the TT rules as a reference for lore stuff.

i didnt know that tyraniding is something that should be encouraged even if it happens in TT ...and wtf is it with you and TT this isnt some TT simulator....

I didn't take armour save into account because my original post stated "Orkz are just as tough as Space Marines except for the armour that they are wearing". So the armour save is irrelevant, even more so being that we are discussing close combat most close combat weapons, once you get above the range of chain weapons, negate armour saves completely.

Being that lore tends to conflict itself anyway, depending on what the story is about and the TT codices are in fact part of the lore and we are discussing a game not a story so TT is easier to translate than a novel, I see nothing wrong with referencing the TT game.

I've read 40K stories where Orkz are the toughest and meanest race out there and butcher marines left right and centre and read stories where marines kill them easily, it all depends what the topic of the story is. If you read stories where the marines are the heroes then they are shown as the toughest out there, if you read stories about the conquests of Ork hoards then Orkz are the toughest. [shrug].

but the orks the story is about are going to be nobz at the minimum, if not mekboyz, painboyz, or somfin else.
if its just a regular ork killing marines...thats just bad terrible writing.

also, there are no books about orks. the hell are your reading??
fanfictions?

Clan histories and short stories in multiple Ork codices from various editions of the game plus Titan legions etc, it's all canon.

To be honest a lot of the novels written about Space Marines display marines as so powerful and every other race as worthless. So basically you have a single perspective unbalanced canon as far as the novels are concerned, I don't rate many of them as worth while for canon information about any other race.

true true.
but the novels are generally about marines that are captains, or at the least experienced veterans.

Agreed, my main point is, regardless of what type of marine the novels are about, the novels a written from the perspective of the marines (and sometimes Imperial Guardsmen) making the marines the protagonists and embellishing their abilities and skill with great detail.

Due to the way that they are written and the biased perspective the novels are useless for analysing Orkz as they don't concentrate on them at all from the Orkz perspective.

Therefore the only lore that we have for Orkz is the TT rules and the short stories in the codices, which means every other faction will and should be judged in the same light to keep balance.

true.
but all of the short stories in the codex's that involve orks fighting are about nobs or higher, now that i read them. they are about orks who are talking about their own mob being better than some uvva gitz mob. an den dey smack a spays mareen in da face or summit'

Agreed there is very little canon story available on Orkboyz, which is why the only real comparison that you have is the TT rule sets (which come with comparable stats), this is why I tend to refer to the TT rule sets in my posts when dealing with faction vs faction comparisons, it's the only balanced objective perspective that we have.