I have a 2ft tank with about 15 cherry, 30 crystal and 5 ghost shrimp
They all live fine with my guppies and my endlers...... the guppies keep popping babies out and its like every few times I actually sit there and watch my tank there's more and more babies from the guppies, endlers and shrimp....
But that's just me... there's heaps of plants and java moss and holes for the shrimp to hide...
When I throw in some pleco algae bits the shrimps and my pleco eat together... sometimes it looks like the have a little battle where the shrimp try to drag the food
But all in all that's just my set up i guess everyone's is different