The concept of Alpha, Omega, and Beta are only aplied to the BL's omegaverse, in that case, Passion is not an omegaverse, therefore there are no Alpha and Omega, Just tops and bottoms.
Betas- They are people like us, only women get pregnant and the betas can't sense the pheromones.
Also Alphas and Omegas usually use their pheromones to establish dominance, so an dominant alpha is stronger than a regular alpha because the pheromones are strongers. :))