Personally I'd up the school numbers too, but that's my personal preference too, not a requirement! But I'd at least get a couple more pandas, cories just show so much better and seem so much happier in larger groups. They clown about more, and it's adorable!
About the otos, I'm really happy that you are going for a group rather than one or two! Not enough people recognise that they're a schooling fish that need a group, so kudos to you for that
I'd add a load of live plants before you get otos though, if you don't have them already. It provides more surface area as a food source for them (they graze algae and micro organisms from the leaves) and they feel much safer and more secure with all the hiding space that provides, which counter-intuitively means you see them out and about a lot more.
If it's a new tank, I'd wait until it's been running for 2-3 months before getting the otos, they fare better in an established tank that has grown enough soft algae and biofilm for them to munch, and they are sensitive so need stable water parameters, a new tank can still fluctuate too much while it's establishing, and as the bioload is changing when you're adding more fish.
Also when you get them, bear in mind that they're all wild caught, and losses are common. Wait until they've been in the store for a while so the store takes the losses rather than you, look for ones that have full, round tummies, and undamaged fins. If their tummies are flat or curved inwards, they're starving.
When I bought mine, they went into a heavily planted, established tank with parameters of 0/0/5, and I still lost one from each batch, so I'd suggest you get a batch of six or seven. If you get five and lose one, you'll only have four left, and mine have always done better in a group of six or more. I have five left in my school in right now, and I'm planning to buy another batch of four or five to bump them up again soon, as they don't school the same way with only the five of them.
