User blog comment:IamJakuhoRaikoben/Chapter 384: Attack of the Stars, Review./@comment-188.83.193.250-20140516191755/@comment-24066070-20140516204831

The Spirits aren't that strong, but that's only normal. Lucy has 10 Golden Keys (or 9 from now on) and she can already summon 3 at once for an extended period of time. It would be a bit overkill if all these Spirits were as strong as Laxus.

The point of Celestial Spirit magic is that the different specialities of each Spirit complement eachother and the summoner, not to send 3 powerhouses out at the same time. I quite like the fact that Lucy has various Spirits which all come in handy in certain situations, after all there are already enough musclebrains in FT.