Well, there is room to wiggle if you are doing weekly WCs, have healthy plants, and watch your feedings. Generally people follow the 1 inch/gl guideline, the idea is that a certain area of substrate, tank walls and filter media can only harbor so much bacteria to process ammonia and nitrite, in a ten gallon there's much less area for bacteria, so overstocking can push the bioload too far and cause a tank crash. Those tetras and most hyphessobrycon species like them are usually 2 - 2.5" full grown and have a meaty diet, you'd add less to the bioload with smaller schoolers that tend to stay 1" or less, like dwarf rasboras. Otos are going to have a mosly plant/algae diet which doesn't dent the bioload as much as a meaty diet, plus they stay small, so you could almost squeeze them in without counting much. Cories can vary anywhere around 2 - 3" depending on species. Your list is roughly 19" total, so technically that is about double stocked, also take into account that tanks usually don't hold the volume that we name them by, so you might be dealing with 8 or 9 gallons after figuring the actual volume then subtracting substrate and the inch or so from the tank rim to the water's surface. If you substitute the cories for a few otos, let them be the main grazers/scavengers, you would be a lot safer. Swap the tetras out for schoolers that are half the size and there is more room for error, and errors happen much easier as the size of the tank gets smaller.
That said, the impact of fish like tetras and cories is not even comparable to that of a pleco or oscar, ten inches of tetras are never going to equal the waste produced by one 10" pleco or oscar, so the 1"/gl guideline is sometimes irrelevant and is truly nothing more than a guideline, not a rule. Still, you have much less room for error in a 10gl than a 20 or 30gl.