I had a 6" Oscar HALF-swallow 4" Albino African Clawed Frog.....I came home from work one day and he just had a LEG sticking out of his mouth and he swam around like that for the next day until it was digested enough for him to finish swallowing.
Jeanine has quite a set-up, but you may want to consider Balas are a schooling fish best kept in groups of 6.........each one has the potential to reach 12" from my sources.
Their size is the reason I don't have more. I haven't noticed abnormal behavior from them. They still swim around the tank together. They don't seem very shy either.