Yeah the cory and otto need to be in groups of 5 and a 20g isnt big enough for angels unfortunatley your looking at a tank that is 3 foot long and 18 inches tall so around 30-35 gallons.
To be fair with 11 mollies I would say you will be pretty much full stocked with the ottos and the cories - if not slightly over stocked adult mollies are sometimes surprisingly large but their genetics vary greatly in the hobby to those in the wild so often dont reach full size but yeah just be prepared to thin your group as they grow and particularly with males and females you will end up with a ton of babies. Hope your prepared as it could get problematic with fast breeding fish with no predators.....
Well the adult marble and 2 adult white lyre tails are the biggest. I have seen them pick off fry before so I think they may help with the population control plus my LFS will be my fry to grow and sell in their shop (I get store credit or cash for them). I figured I was going to be a little small for angels. thanks for the info!