I am well aware of that, if given great care its not unheard of for them to reach between 14" to 16". However, like you said, 100 gallons for 2 oscars. The senegals get to be about 15" MAX but more typically around 9" to 10". The twig catfish doesnt really impact the bioload all that much since he may be the longest but as the name implies, he is the size of a small twig. So, given good feedings, no decomposing food, good filtration, and regular water changes, how do you feel a 125 would not work for these fish?