Note that in Japan, the Full Art and Alternate Art cards are considered Secret Rares, while the English-language Pokmon TCG classifies Full Art and Alternate Art V as non-Secret Rares, saving that label for Rainbow Rares and Alternate Art VMAX cards
Garruk is a little safer to flop onto the board, comes out sooner and easier and kills a little quicker than Bolas
This means you can play it on any other character that you already have
It can also be used to hit any Pokmon of your opponent's, including those on your bench, so it can pick up quick points against weakened enemies
Many collectors will still pay more for an English card in PSA 10 if its a grail like Base Set Charizard, but for newer cards some prefer the Japanese version which might be easier to grade 10
While I've never loved outlast as a mechanic, his clever use of those creatures as a way to give his army abilities because of their +1/+1 counters makes a lot of sense and really works in a 3-color deck