For anyone interested in this unusual variant:
We just played one, and it worked reasonably well. Best done in friendly mode so either player can request a mulligan if the draft results in 2 animal action cards, or 1 animal action card and 2 of another type of cation card, because it wouldn't really be fair if one player had to play with a specialized animals action card.
The game took 50-51 turns, which is probably to be expected since the options for increasing appeal are limited unless some crazy combination happens with the pavilion build card and Engineer and landscape gardener or something like that. Which might as well be a re-do anyway since I can't think of any way to win against that.
Our game was reasonably competitive, and I realized later I made a really stupid decision in the draft by picking a usually good card that wasn't much use in this variant, and passing up one that is very useful in this variant. (Even worse, not only did I not draft it, but I passed it back. Whoooops.)