After the disaster that was The Last Outpost, I found Bok in The Battle pretty threatening. Though you could tell right away they were already trying to undo the damage of the previous episode by making them less harsh. They went a full season before seeing more in Peak Performance. There they were foolish, yet threatening.
The setup in TLO is really hard to shake. For one thing, they were played by short actors, who hunched, and acted like street hustlers, (to say nothing of their monkey mannerisms).
Contrast that with DS9's first impression of the Jem'Hadar, who kamikaze'd a Galaxy Class starship. Or even Q, who first appeared as a space barrier and then a god. First impressions are everything.