I'll give you my stock list in my 20G half-moon to give you an idea of what's possible. AquaAdvisor is a good tool to reference, especially for the beginner aquarist, but it is by no means an accurate estimation. If you have a medium-to-heavily planted tank, then AquAdvisor can be thrown out the window...or Alt-F4'd.
Here's what I have and tank is stable (it's been stressed and still stable) and I would consider it medium planted (having revisted it)...
7 Harlequin Rasboras
2 Badis Badis
6 Neon Tetras
3 Bloodfin Tetras
2 Bubble Rams
2 Bumblebee Gobys
2 African Dwarf Frogs
2 SAE
4 Golden Ottos
5 Corys (2 panda + 3 pepper)
1 danio (not a normal resident)
1 chili rasboras (not a normal resident)
5 Amano Shrimp
~5 Cherry Shrimp
All fish are showing colors beautifully. Tank has been stressed with overfeeding and no ammonia spikes. Most of its due to the large filter (Eheim 2215) and the plants. I also spot feed bloodworms and the like - things that would release a lot of ammonia if left to degrade in the tank.
As far as your ottos go...they school beautifully in larger numbers. 15 + would be appropriate in your tank, imo. 50 Harlequins, although an impressive number, wouldn't look all too great, imo - they're more accustomed to being a background fish rather than the main attraction - in your case they'd probably be the Roselines.
As far as stocking levels go for biological safety, you're way in the clear, especially so if this thing is medium-heavily planted with good filtration (if you meet the needs of good CO2 - water movement reached with good filtration + powerheads, then its more than enough for fish safety). My tank is low-tech with only the Eheim 2215 (more than enough imo). You'd be surprised what a good filter and plants can handle in terms of biological waste/ammonia/nitrites/all the bad stuff.
My advise....first stock the tank with the fish you want most. Although I honestly think you're far from stocking limits, when you get to finishing your stock list, add the fish in slowly to see how the tank handles it. Simple as that. Space out the latter fish species/numbers and you'll be fine.