Strictly speaking, I'm not sure if any of these qualify as fallacies - a reminder that not all propaganda is fallacious.
Native Americans were fighting each other before white people even got
here. Humans have been fighting each other from the beginning of time.
That's literally true. Whether or not it's justification for European colonization is a matter of opinion.
My perspective: Most Native Americans were forced to defend the resources they needed to survive from other tribes, as growing populations increased competition. That's called survival.
Europeans' survival, on the other hand, wasn't dependent on discovering and colonizing other worlds. Moreover, Europeans effectively waged war against the environment to boot.
That's one rebuttal you could use against this particular argument. But, again, I don't think it qualifies as a fallacy.
Argument: "X corporation's lobbyist's leverage their wealth to
influence Y politician." Rebuttal: "That sounds like all corporations
Again, that sounds like a weak fallacy at best, since greed and corruption are rampant and apparently increasing. One could quibble over the word "all," but prefacing that sentence with "That sounds" suggests that they aren't attempting to make a precise statement. It sounds like they're simply saying, "So who is NOT corrupt among politicians and corporate tycoons these days?"
Possible comebacks might be "Two wrongs don't make a right," or "Enough is enough! Where do we draw the line?"
Argument: "Native Americans land was taken from them by force and
deceit." Rebuttal: "Native Americans aren't native. They came to the
Americas from somewhere else just like the rest of us."
In fact, Native Americans DID emigrate from the Old World.
We could quibble with the phrase "just like the rest of us." They certainly didn't arrive on high-tech sailing ships. In fact, most probably migrated across the Bering Land Bridge during the Ice Age.
Another point: After living in the Americas for thousands of years, the first Americans adapted to the environment. Their cultures were essentially tied to the land.
In contrast, many Europeans were largely divorced from Nature even before they left Europe for various colonies. Most Europeans' roots in the New World are relatively shallow, and their cultural links to the environment - aka "Mother Earth" - are equally shallow.
There's a difference between "native American" (e.g. native born) and "Native American" (note the capital N). Most of the latter can also be called Amerindians, but there's no such thing as Amereuropeans, as far as I know.