At level 11 the polar bear has +7 to hit and is dealing 1d8 + 5 and 2d6 + 5 damage and has only 42 hp.
The ranger at level 11 presumably has +9 to hit and is dealing say 1d8 + 7 damage(dueling) twice

If the ranger hits at ~ 65% the polar hits at around 55% for a total of 12 + 15 ~ 27 dmg

An equal level fighter with dueling will have +9 to hit and deal 1d8 + 7 damage 3 times for 22.5 dmg so it is probably over-tuned a bit.