well, the advantage this would have over both those cards is with catapults +50% damage bonus when using frozen creatures, and-
over voodoo : mono element
over amigos : much lower cost
but a minor boost to hp may be in order- looking at the damage table in
http://elementsthegame.wikia.com/wiki/Catapult8 hp for the basic may be more suited, to deal 12 damage, normally would take a 13 hp creature to do that damage
10 hp for the upped seems fine, it will do 15 damage, which will normally take a 17hp creature to do that damage