>Some of those words they brought over might still be around

A lot of those word are still around (in one form or the other). For example at least those written in italics:

The words the Germans brought came from somewhere too. They didn't just create a new set when they moved to the British Isles.

"They" is of Scandinavian origin, by the way.

Right, so the older version of those words would be found in Germany.

Yeah, but I'm saying that, based on the contents of the article, a more accurate title would be: "Oldest human words that still happen to be used in English found"

The words they discuss are really more 'sounds with meaning' where the sound hasn't varied much relative to the meaning no matter which language or time period you look in. Just because the language 'English' wasn't differentiated before some century doesn't mean the words didn't exist.

The article title is poor - it should really be oldest indo-european language words found. There are dialect words for 1,2,3 etc in England that are considerably older than English (the people or the language).