And what would you learn from that? Even if it could be said that those things attempted to implement that strategy and failed, you can't really infer much about its overall viability by looking only at losers.

The dodo bird is an example of something that was isolated and then got steamrolled when the herd came around.

You can always zoom out and look at the bigger picture, it's not even about individual species but life as a whole. "Hide and isolate and wall off" is not successful in the long run.^ Your only chance is to keep up with the herd.

If we look at human civilizations, which ones successfully isolated and hid from (real or hypothetical) bigger badder ones? Neither isolation nor annihilation is ever a winning strategy. Fear is the mind-killer.

^ Save for things like extremophiles that have found their way into a tiny niche that nobody else wants. They may survive but they don't flourish and prosper.