That might be an understatement, at least according to his enemies ...... From what I understood in the readings about him, he was a pretty rough and tough type of guy.
Still, he was a mighty king, and a fair one, and such one that the people of Rohan needed in those desperate times.
On the symbolism ... it goes further than the hammer and his name:
- 2758-9: Rohan at war, Helms Deep under siege, Helm Hammerhand the last of the first line of kings in Rohan, the title passing on to his sister's son Fréaláf
- 3018-9: Rohan at war, Helms Deep under siege, Théoden the last of the second line of kings in Rohan, the title passing on to his sister's son Éomer.