You can exploit some gods. For example: Start with Gedo to get an experience bonus early on and empty some chests near e.g. mammoths. Kill some animals to get rid of Gedo and choose another god.
With "best cards" I wasn't referring to a single card. There are countless ways to win in pvp and you really do not need to spend a single dime to get to the top (and by no means to get through that campaign - strategy beats money, money may safe time) I am not sure, if that "top tier artifact stall" is a strong strategy (I personally never had problems with artifact based decks so far thought I am far from being top tier yet) but certainly it isn't a free win (even less with all those new (and old) easy to get anti-artifact cards).
 "Wondrous Lands"){kind=icon}
 "Nightbanes"){kind=icon}
 "Heroes of Glory"){kind=icon}