Permafrost
x4
1
Seek Power
x4
1
Torch
x4
2
Equivocate
x4
2
Strategize
x4
3
Display of Instinct
x4
3
Howling Peak Smuggler
x4
3
Jennev Merchant
x3
4
Sandstorm Titan
x4
5
Jotun Hurler
x3
6
Heart of the Vault
x4
6
Howling Peak
x4
6
Xo of the Endless Hoard
x4
Fire Sigil
x4
Primal Sigil
x2
Time Sigil
x3
Crest of Fury
x4
Crest of Impulse
x4
Crest of Wisdom
x4
Seat of Fury
x1
Seat of Impulse
x2
Seat of Wisdom
x1
View Deck on Shiftstoned
Clan Standard - Potentially better removal than Polymorph
Unseal - If you feel like you want another counterspell
Hailstorm - If you feel like smaller units are an issue.
Rain of Frogs - A reasonable hate card in some metas, though maybe not this one.
Honor of Claws/Jotun Feast-Caller/Mokhnati, Restored - Sometimes you just want to draw cards.
Mortar - Site removal
There's also the option of playing a fire market and turning the Polymorph slot into something like Jawbone Greatsword, Cauldron Cookbook, or Obliterate.
Yet another option is to put a copy of Peaks in the market ether by playing non-smugglers (I.e. Jennev and Ixtun merchants, cutting Torrential Downpour for something like Rockslide) or cutting it from the main deck.