>>53722184imo Acerola > Mina = Hau > Lana
Obviously depends on what units you already have. If you have the Pikas there’s not much point going for Hau, same with Lana vs any of the large number of limited psychic units.
Between Acerola and Mina, Acerola just has a much better-defined use case, since her entire kit is geared towards supercharging physical grass damage dealers, which most of the good ones are.