if everyone in the world turns into white zetsus whats the 'army' for

[ᖇ α z m α η]

Everything [with chakra] will be affected by Mugen Tsukuyomi,thus turning into White Zetsu gradually

The army is most probably needed to dominate the universe :/

 

[Angelic.]

if thats her dimension maybe it got destroyed by some being and she left to eat the fruit and rebuild her home on earth? lol. maybe she grew to hate humans after a while instaed of protecting them. anti superman

 

[AaaaNinja]

kaguya never said she wanted peace

The reason she ate the fruit in the first place was to stop all the fighting.

 

[MAN OF SIN]

The army isn't for anything, Kaguya wants Eternal peace with no conflict. If the world was populated with mindless Zetsus that obey her every order well... You get the gist

Black Zetsu flat out said that they are for battle.