I bought 4 shrimp to put in a 5 with a betta and 3 endlers stowed away in duckweed that was in the bag with the shrimp. Fast forward 4-6 months and I had 3 -4 dozn of each. Might not be ideal but the 5 won't stop them from going about their business.
Have a endler and shrimp tank. Never have seen a baby shrimp with the endlers, but have seen baby shrimp in my shrimp tank. But on the other hand, I have seen it done and work. Just doesn't for me.
Tho my water is so horrid that I lose a full grown shrimp almost daily, started off with a good bag of 100 cherries and has dwindled to about 25 or so. Can't wait for my ro unit to show up Friday