Guppies will cannibalize their young. They will pick at your shrimps as well. They are never full.
I once had my cherries with juvenile guppies in a 5g. The colony started out with 9 that was whittled down to 2 in less than a month!
I ended up buyimg more neos and with the 2 survivors, they now live in a 10G. I finally succeeded in having a berried hatch shrimplets who are thriving.
I know the 5G is too small for the guppies so I will rehome them soon as well.
Of those options, my vote would be “massacre.” I do nano tanks and I’ve never had them eat eachother alive, although dead is definitely fair game. Really odd that it would be guppies tho, but possible. You don’t have any ghost shrimp or assassin snails in here or anything else, do you?
outflankedlala 
Guppies will cannibalize their young. They will pick at your shrimps as well. They are never full.
I once had my cherries with juvenile guppies in a 5g. The colony started out with 9 that was whittled down to 2 in less than a month!
I ended up buyimg more neos and with the 2 survivors, they now live in a 10G. I finally succeeded in having a berried hatch shrimplets who are thriving.
I know the 5G is too small for the guppies so I will rehome them soon as well.
Of those options, my vote would be “massacre.” I do nano tanks and I’ve never had them eat eachother alive, although dead is definitely fair game. Really odd that it would be guppies tho, but possible. You don’t have any ghost shrimp or assassin snails in here or anything else, do you?