[GodGunsGuts]

So, you’re saying that mixing and matching of ERVs via recombination would not give the false appearance of age, given the assumption of common descent?

[allmendream]

What do you mean by “mixing and matching of ERV’s via recombination” and why would you assume that it would make the exact same pattern that an ERV incorporating into a common ancestor would make with ‘older’ looking ERV’s being widespread among species and ‘younger’ looking ERV’s being only in a few similar species or only a single species and the ‘youngest’ being present only in some members of that species?

Recombinational deletion is a detriment to an ERV getting fixed into a genome, it isn't “mixing and matching” ERV segments. Do you mean transposition, which is where a very “young” ERV still has transpositional ability and can “get up and move” in the genome? That doesn't “mix and match”.