i dont like omegaverse for many reasons, but

not the bottom but the alpha is shorter
http://www.mangago.zone/read-manga/unromantic/

alpha bottom: http://www.mangago.zone/read-manga/a_tough_alpha_wants_to_be_loved_cornered_by_a_young_omega/

alpha bottom: http://www.mangago.zone/read-manga/sutenaide_my_hero/

alpha bottom; http://www.mangago.zone/read-manga/boku_no_high_spec_kareshi_sama/

they're a switch couple but alpha is bottom first: http://www.mangago.zone/read-manga/like_a_tidal_wave_from_pheromone_shower/

both are alphas: http://www.mangago.zone/read-manga/imitation_mate/

both are alphas: http://www.mangago.zone/read-manga/okusama_ha_alpha/

both are alphas: http://www.mangago.zone/read-manga/alpha_ga_alpha_wo_daku_houhou/

Thank you(๑•ㅂ•)و✧