Here scribe 2 of 𝓟 seems to have accidentally omitted the repeated subject pronoun we when he copied from 𝓞 into 𝓟; Oliver Cowdery supplied it when he proofed 𝓟 against 𝓞 (although Oliver supralinearly inserted the we before the conjunction and ). It is very probable that 𝓞 had the we since in this conjoined structure the repeated subject is optional.
Summary: Accept in Alma 12:14 the we that Oliver Cowdery supralinearly inserted in 𝓟; Oliver undoubtedly intended the we to follow the and.