Ever hear of the Huns?
They may designate them central Asians.
But it is a weird thing to say. Especially when obvious visually.
East Asian migration to Europe made a full 5% impact on ALL European populations. With small populations, the migration of a few mighty hunters, or the importation of a beautiful woman could have a massive impact.
The Huns added a very negligible amount ~ same for the Mongols, etc.