Great guide. I've never played big beasts (I didn't have some Nature cards in winter and was focused on Deception) but I played against them so I remember well these things. I don't have Finnian, Selena, Boars, and Chiron however. But no problem, I think.
Valewarden is great.
Lethal Prowler is an interesting card (I recently saw it in a Deception deck playing against me), it might fit a big beasts deck. When other friendly creature attacks, LP attacks the same character once per turn. It can attack the god on the turn it was summoned - godblitz. I want to try it in my Guild Zoo Deception deck especially against Magic.
Big Beasts? Probably, I should try.
Definitely! I'll be interested to see what deck you put together.