I remember broken English in Caldera, everywhere else, in 3 and 4, I remember hearing perfect grammar from every orc.
As for the other stuff. You're right, that's how it happened in the lore. But it doesn't suspend my disbelief. No way a big, green pointy-toothed monster is gonna blend in after centuries of bashing in the skulls of Tamriel-folk.
Yes there are orcs who grew up in the empire, but it's unrealistic. Because any orc who starts a family in a human or mer settlement 20 years after the warp in the west is insane. It's one thing to have your family move in with you to the legion fort (the towns around legion forts in history were reserved to the soldiers and those who served the soldiers), but to be walking down the street in an Imperial city?
Nope. Just look at New York city in the 1800's. And the immigrants the New Yorkers lynched looked just like them. The orcs would stand no chance. And as if some legion soldier would risk his neck, breaking up an angry racist mob just to help some smelly orc. The legionaries are gonna look the other way. Even if they'd fought side by side with an orc in the past. Meeting one or two honorable orcs doesn't do much to quell one's distaste in an entire race, in general. Especially when that hate has been conditioned into one's head since childhood.
I thought you didn't like real world comparisions
And yet the immigrants continued to move to New York and their descendents live next door to descendents of the people who tried to lynch them. And the people of Tamriel are much more cosmopolitan than we are. They're used to people who look very different to them. You're wrong about what the Legion soldier would do IMO. If hes fought besides orcs and an orc needs help and he thinks the orc was a former legionary he'll help the orc. Soldiers always think better of former comrades than civilians in my experience. The Watch might be another matter. Never seen an Orc in the Watch and since the Watch live amongst the general populace they're likely to share more of their prejudices.
Orcs were never wilderness dwelling savages by choice, the 2 Orsinium's show that. Crude imitations of human cities they might've been but still when they had the chance they chose to build and live in cities.
Hate is a much more powerful emotion than you or the writers at bethesda give it credit for.
Even in places that are a byword for ethnic tension like Jerusalem or Bosnia people of different races manage to live together without conflict most of the time. When law and order breaks down then things can get very nasty very quickly but if there is law and order and its committed to keeping the peace most people tend to keep their feelings in check and get on with their lives.
As for the Dunmer opinion on Argonians: ask any Imperial if he gives a crap what the Dunmer think. The rest of Tamriel views the Dunmer as depraved, violent perverts. If the Dunmer hate the Argonians, then the Argonians must not be so bad.
Then again, I could see a mob of angry Colovians beating an Argonian to death because they mistook him for a lizard man.
The point I was making is that despite their old hatreds the Dunmer and Argonian don't attack each other on the streets.