Lets look at the Haki users from Pre-TS:
-Satori, Gedatsu, Shura and Ohm, they can use Observation Haki, Ohm looked stronger due to his special iron cloud sword, without that he would be weaker.
-Marigold was able to use Barrier armament Haki.
Enel's priests such as Satori were much easier opponents, while Pre-TS Luffy needed G2 bazooka to overpower Marigold's Barrier Haki. Luffy's regular DF attacks were not working vs Marigold while those regular DF moves were enough vs Enel's priests or vs Enel.
Or lets look at people like Otohime, natural born observation Haki user. While people like Sentomaru when they are kid (possibly talented at armament Haki even he was a kid) would be stronger than natural born observation Haki users. So being natural born armament Haki user is better than natural born observation Haki user.
And kid Ace when he was being hold, and still knocking out Bluejam pirates with 1 move or kid Doflamingo when he was tied with ropes knocking out people who were trying to kill him is a much better power than those as well, plus making people and animals around them tamed.