Canada

Yes, the Germanic tribes most certainly did eventually impose their culture and law on the Romans. Do you remember who sacked Rome in 410? It was Alaric of the Visigoths, which was a Germanic tribe. The Visigoths definitely imposed their laws, the Visigothic Code, when they could on the territories they colonized. And that was after a couple of hundred years of various Germanic tribes setting up relatively peaceful colonies in the Roman Empire. After they sacked Rome, they wanted to adopt the authority and prestige of the Roman Empire, so they became foederati, left Italy, and colonized southern Gaul. Then they colonized Spain by booting out another Germanic tribe, the Vandals, and imposing the Visigothic Code on the locals there. However, this weakened their position in Gaul, so the Franks came along and booted them out, imposing yet another culture and set of laws and creating the basis for modern France. Then the Arabs came along and defeated the Visigoths in Spain and imposed yet another culture and set of laws. Et cetera, et cetera, et cetera ad infinitum for all of human history. So, remind me again who the bad guys and the good guys are?

Edit: And with regard to North America, I wouldn't say that Europe colonized North America in any kind of organized way at all in the beginning. European countries competed with one another for land and trade, and many colonists were independents fleeing religious persecution in Europe. My first ancestor in North America was a poor French farmer who left Europe in 1650 because the nobility owned all the land in Europe and he didnt want to be a serf. He didn't have some evil plan to trick the Indians and eventually take the whole continent. His small group of farmers didn't even bring many women. My ancestor married a local native girl. He and his little group largely integrated with the native people. They got the benefits of French farming techniques and crops, and he got the benefits of a new family and culture and the know-how of the locals. Of course, the Church also came along an their motivation was to convert the natives, but from their perspective that was about saving souls (misguided as that was), not conquest and genocide. A while later, after many more Frenchmen had migrated to North America, the French nobility became more interested and the king decided that he would make a more serious claim, but even then he was mostly trying to keep the British out. The French largely remained allied with the natives. Eventually, it got to the point where North America was no longer just a source of furs and an outlet for unpopular religious minorities in Europe and colonization kicked into high gear. The natives were literally at the Stone Age level of technology -- no metal-smelting, no written language, not even the wheel -- so they simply had no ability to maintain their sovereignty and culture once the European machine really got going, so they got steam-rolled. Thats not even considering the terrible effects of being exposed to Old World diseases that they had zero immunity to. Modern estimates are that 90% of the indigenous population of North America died of various Old World diseases long before serious permanent colonial expansion began.

My point is, once again, that many people have been indoctrinated to a narrow, black-and-white view of colonization. It isn't a separate thing from migration, it is one part of the continuum of migration. If you think of it on a continuum, it becomes hard to sustain the binary good vs. evil narrative that you seem to be stuck on.