What would be the number you'd consider "flooding"? As soon the significant instability is introduced, it's too much. It depends on the effects, not on the numbers alone.

Good question and I couldn't tell you offhand - but I will stand by my disagreement with "+0.4% from migration is flooding" when "+0.9% from births" isn't.

Babies don't often bring foreign cultural norms and overwhelm social services. Which is why one might be flooded with migrants, but not babies, though there be more babies. It's why rain might cause flooding but not snow. The snow may cause a flood later, but not now.

Can you cite some evidence for "overwhelm social services"?

How 'bout the part where they're dumping the migrants into small villages and anywhere they can because they don't have sufficient housing for them?

This is true, but consider the number of births attributable to refugees and other recent immigrants, and consider what kind of cohorts are coming in, and where - the entire EU isn't receiving an even distribution of immigrants.

Mohammed is the most popular baby name in London. The young-adult-male cohort in Germany will soon be dominated by peoples of Middle Eastern origin - most Germans are old, and immigrants are largely young and male. In countries like Sweden, fully 20% of the population is foreign-born or born to foreign-born parents. Cultural change is definitely coming to the EU one way or another. For hundreds of years, until around the 60s, most European countries allowed virtually no non-European immigration. Given the birthrates of native Europeans, we're talking about total demographic replacement in a few generations in many countries. I find it hard to believe that's not going to cause some instability in the short to medium term.