I believe they really are anti-c for everything, including Sadism. What they favor is expressing sadism, not acting on it, which as far as I am aware was never a problem for most pro-c Zoophiles. There was some politics around pro-c Zoos not allying with Zoosadists after the Zoosadism controversies - although I recall anti-c's got very worked up about this, because as I say most anti-c Zoos are pro-sadist, pro-fictional-not-acting-out.With this in mind, sadistic anti-c zoophiles genuinely terrify me.
One of the IMO deliberately instigated controversies was the idea (by anti-C's) that Zoosadists were a kind of "Zoo" - and this (as always happens with this kind of truth games) was offered as an answer to which any compromise was "fascism".