All the right points have already been made, incompatibility, way undersized tank, not releasing captive fish, we all hate to say it but I think all of our first plans were shot down eventually thanks to good old mother nature and her order of things. You're about to learn to why large fish and planted tanks don't work. A wood dominated scape with floating plants, maybe some leaf litter in a huge tank over a couple hundred or a thousand gallons could make this idea work great given the species decide to live cohesively. Aside from all the technical reasons why this won't work well, I think you'll come to find that huge fish in smaller tanks, especially planted, creates a tacky clutter that destroys any chance of creating and enjoying a proper aquascape, whether the fish is a species that destroys all creation and devours all life, or simply floats out in the open all day.
Sounds great for a big fish tank aside from some species incompatibility, but for a 'scaped planted tank, choose the fish as ornamental and be conscious of their effect on the overall scape.