For weapons you'll have going into mountains the damage (ignoring skill lvl and assuming each weapon is maxed) per hit is:
Iron Mace is 73
Pickaxe does 48 x 2.5 due to the golem being very weak to pickaxes and resistant to piercing, so 120 damage.

The Iron Mace however attacks faster and can combo giving it a higher dps, but can be more risky as it requires you finishing the 3 hit combo to get the benefit of double damage from the last hit. Bad timing means a guaranteed hit from the Golem. You'll need a fully upgraded banded shield or better plus a high block level to block/parry.
The pickaxe you want to jump attack because having it hit an object at the same time reduces damage by 33%
So they have their tradeoffs and it's really about your approach.

But don't use Frostner against Golems when you get it. Golems are immune to both spirit and frost, which means only 30% of its damage has any effect at all, that's 35 points regular damage.