Help with ghost shrimp

[Lots O Pets]

I have a twenty gallon tanks with 9 adult male guppies, a bunch of baby guppies under two months old, a otto and about 13 ghost shrimp. I am going to sell the adult male guppies and and I am going to get 5 more ottos. My shrimp have eggs and I want to keep the babies so I wondered if the baby guppies and ottos would eat the baby shrimp? or would I be better off putting the shrimp in a 10g of their own. Also how many could go in a 3g tank? Thanks