well.. if you go by the "Inch of fish per gallon of water" guideline, then I'd say the 3 ADF and 2 Otto come pretty close to filling your 10g tank. The ADF grow to an 1 1/2-2" and the otto's 2". Its my understanding that the frogs produce more waste than a comparably sized fish, so you might want to round up and say that its full.
Its just a guideline, however. You can go beyond it, but the further you go the better filtration and more physical upkeep on your part will be required to keep them healthy. What kind of filter do you have? Are you going to be able to do PWCs more frequently?
I think the neons will have a lower bio-load than the guppies, so if youre going to add more then those would do better with your current stock.
