User blog comment:MagnoCosmos/Celestial Spirits Ranking/@comment-7418318-20150907194818/@comment-7418318-20150908211415

You talk as if more numbers automatically mean victory... it does not. Quantity has a quality of it's own, but that doesn't mean it's a win-all card.

From Mard Geer's words we know that as the Summoner loses power, so do the Spirits.

Sure Gemini can summon two more Spirits, but we have no idea how that would translate into power drain. It might well be that if Gemini summoned Spirits, the cost of keeping Gemini around would increase greatly.

The only time when we saw Gemini summon a Spirit for Lucy was when they came under their own power without having a contract with Lucy.

Then there's also the matter of Lucy-Gemini when Angel used it. Angel didn't make Gemini summon any of Lucy's Spirits, except for Sagitarius. Angel was very clearly an expert of Celestial Spirit Magic and cruel enough to greatly enjoy Lucy being tormented by her own Spirits and yet she didn't do it. Isn't that a pretty good indication that it isn't as easy and straightforward as you make it out?