I would argue that Levine did more damage, since none of Arnold's doings had any direct effect on the series in production at the time.
That's a fair point.
To some extent, I think Arnold's damage is longer-lasting, because his views have prevented Star Trek
from being a multimedia franchise in the same way that Star Wars
or Doctor Who
are because in the Arnoldian view every tie-in is automatically irrelevant. Compared to other IP franchises, Star Trek
has never mastered a multi-platform synergy. I would say Star Trek
hasn't even tried
. And I think that can be shown to be a legacy of Richard Arnold and his views.