Normally, this means the token will simply be a Compy Swarm, but if any copy effects have affected the original Compy Swarm, the token will take those into account
However, in the context of Lurrus, that inefficiency is worthwhile as a source of long-run gas
Overpowering Attack will be great at three mana, but its also perfectly fine for five mana in decks that care about extra attacks
It also nullifies your opponent's graveyard - pretty backbreaking for strategies like 'Dredge' that rely on the 'yard - and allows you to grab your opponent's best threat from the void and play it free of charge (Okay, at the cost of its own life, but it's a lowly two-drop, so who cares?) Paired with targeted discard cards like the popular Thoughtseize, Dauthi Voidwalker has the potential to be super scary
You like Commander? Even better