Lionesses in a vacuum are weak units, since their cost and abilities don’t compensate for their very low stats. However, the Lioness’ main role is to be a target for boosting. As a result, Lionesses are the most efficient way to get to the goal of 5 boosts for Chant of Power, as it is the unit that benefits the most from having multiple boosts.
Abua has kind of an embarrassment of riches when it comes to boosting, and this common is really the only one where you are happy to boost it 3+ times. If you don’t plan to boost the Lioness 2 or 3 times without much effort, then you would likely be better off finding other ways to spend your resources.