Maybe those would be good but I thought it might make the deck strained (perhaps more strained) on water quantum so I stuck with something that would definitely improve the deck. Plus petrify is a bit overkill with all that freezing. To use earth nymphs and have the right amounts of quantum one would have to considerably change the deck and I'd rather improve arena decks as they are then change them to something with another strategy even if the decks are similar.