Since Thx rarely answers questions. We don't know when he took the docs. I don't think it matters much since he never should have taken them in the first place. I suppose if he took them as POTUS, it could have been done unwittingly since he appears to slip in and out of reality now.
Did he put up a fight and force the FBI's hand - no. I suppose that makes the Biden situation slightly better than Trump's, but it doesn't excuse him.
Has Biden denied having the docs, claimed he unilaterally declassified them, claimed they were planted, etc, etc, etc??? No, no & no. So Biden has handled this situation like an adult, but in the end he still had multiple chaches of classified docs and should be condemned for that.