The hero trio (Puzzle room)

The room is a standard sized room with a beautiful, intricate braided pattern engraved into left and right walls. On the wall, opposite to the entrance is a blank iron door that is behind a portcullis door with iron bars. In front of those bars is what appears to be a steel mesh door that is activated on a pulley system. The floors are stone and the room is barren except for three statues in the middle, sitting on pedestals. They are all life-sized, and very well crafted by the artisan.
Left is a gnome holding a set of unbalanced scales with two large plates.
Middle is an elven archer with her bow drawn towards the entrance of the room.
Right is a dwarf holding a very beaten up, and even seemingly eroded, battle axe.
When enough weight is placed on the scales of the gnome, the first steel mesh door will rise, and the elf will fire its arrow across the room into small slit in the stone, a clicking sound will be heard from the dwarf statue.
The dwarf statue can now be rotated, and if faced towards the exit wall, a mechanism will be triggered to cause the portcullis bars to fall into the ground, and cause a portion of the floor to fall several inches downward, and slide inward, revealing a relatively large and short gaping hole at the foot of the exit door.
This hole is a key hole that can be picked (DEX DC20 Thieves’ tools), but is meant to be inserted with the dwarf’s axe, which is not beaten up as originally described and likely assumed; It’s a large key.