About 40 years ago, in One Piece world, there was a powerful pirate group called the Rocks Pirates. They were at their most powerful at these times, to the point where the World Government was afraid of them.
Haki Types: Observation, Armament, Conqueror's
Big Mom's Haki abilities are incredible, even if she relies more on her Devil Fruit. With a single blow, she knocked down Page One with her Conqueror's Haki.
Haki Types: Observation, Armament, Conqueror's
Kaido was without a Devil Fruit power for a long time. He would only have to rely on Haki during this period. In the end, Kaido was able to train all three Haki types, and he did so in a way that allowed him to grow into advanced forms of each.
Haki Types: Observation, Armament, Conqueror's
Given his legendary status as a pirate and his ability to challenge even Roger, it would be totally foolish to believe that he lacked access to all three forms of Haki.
Haki Types: Observation, Armament, Conqueror's (Unconfirmed)
It wouldn't be a stretch to believe that Gloriosa might also have access to all three of these haki types, since Hancock, the current Empress, has access to all three types.
Haki Types: Observation, Armament, Conqueror's
Whitebeard mastered the ability to use all three forms of Haki very effectively. Conqueror's Haki was certainly his strongest Haki type, and he used it to his advantage in his later battle with Roger.
Haki Types: Observation, Armament, Conqueror's (Unconfirmed)
It would be stupid to believe that he didn't have acess to Haki. One strong pirate of his era was Captain Rocks, who was considered to be the strongest.