I can see the stats being similar to Fire, but Air? Air has creatures with stats: 1/1, 3/2, 3/3, 3/7, 9/6. The stats 5/1 aren't similar to those. The closest similarity in cost is Lava Golem, but it also has the ability to increase it's Attach and Health. This card cannot on its own.
'The balancing system' doesn't always work for every card, as in the case of this card. The cost makes it playable and not unbalanced.