Could be, moving significant numbers of various ethnic groups was something the Romans did a lot; also, ultimately, survival of a given strand of chromosome is luck of the draw.
Yup. That's why they're often surprising. I was expecting mainly Celt and maybe some Roman with a smattering of Viking.
What I got on the male side (in descending order) was Frank, Visigoth, Ostrogoth, Danish Viking, Saxon, Celt.
Of course genes from archaeological samples are hardly a representative sampling. But it's still fun to look at.