Ecosystem ideas need feedback please!

Hey I'm trying to make an ecosystem in a 50 gallon, a 60 gallon hexagon, and another one in a 220 they'll all be a paladarium. I have been gifted a few of the red eyed Crocs. I don't know what can go in there with them I'm trying to make a self sustaining ecosystem. It will have weather and daytime nighttime changes. It will hopefully mimic they're natural habitat. I am trying to figure out what they live with in the wild but I am not coming up with anything good yet.

I originally planned to house some small fresh water crabs, shrimp, snails, fish. And some land critters like isopods, springtails, mini scorpions whatever tiny one that lives in the jungle, earth worms, worm snakes crickets, maybe some small colorful beetles or something. Yes I'm fine with them eating all of these if they want to. Then as far as my top of food chain animals I hadn't figured out exactly what I wanted yet. I know I'm doing a jungle environment.

Now I have these croc skinks and everyone is telling me they're nocturnal. That's fine but id also like to put something non-nocturnal so we have some things out at all times. I was thinking some day geckos possibly? Not sure. Something colorful hopefully. I know it has to have high humidity because of the skinks. I am purposefully trying to imitate they're natural habitat and environment. Please let me know ideas.

Someone else has also mentioned surrendering a blue tongue skink I feel like putting them together may not be a great idea because of how much bigger the blue tongue is. I may be wrong and if they can live together please let me know.

Please let me know what y'all think! Thanks! I am 100% open to any advice you guys have!