How would I size down/de-understock this setup for a 40 gallon breeder tank?

[Mint]

I found this on YT.

Anyways, I love the look of the tank, but I’d rather not have the overstocked betta setup. How could this be sized to a 40 gallon breeder, equally heavily planted, with little/no overstocking? I’m planning to basically copy his heavily planted scape. It has female betta, Rummynose Tetras, Ember Tetras, and Neon Tetras (He calls them cardinals, but they’re most definitely neons).
Also, a side note: are those dither fish actually good dither fish? Will they fin-nip? Do they school well?

 

[seangee]

Just don't add fish.

I only watched a few snippets and in those saw multiple bad practices but I won't dwell on them.
This is a planted garden and the fish are only there to enhance the appearance of the garden with no thought to the needs of the fish. Tetras like low light with low flow. Bettas definitely need low flow. If we were to re-visit this tank in 12 months would any of the fish still be there? (and would they even care)

Not sure if they mention this but high tech means high maintenance. When I had my high tech tank (450 litres) I was spending hours every 2 or 3 days pruning, testing and adding ferts. It was just too much work to keep it like that. The idea that the fish will provide all that the plants need is nonsense. For me that's a conflicting approach to what I believe. I keep plants for the benefit of the fish. These guys keep fish to benefit the plants and for decorative reasons.

Today I still have heavily planted tanks (by which I mean tanks that contain a lot of plants), but no bright lights, no CO2, minimal ferts and low flow - I just choose plants that can thrive in those conditions.
FWIW my approach does not mean I am doomed to ugly tanks - this one gets almost zero maintenance and is very low light (as is my signature tank)

 

[CaptainBarnicles]

I like MD a lot but he doesn't give much thought to the requirements of the fish. He must have some magic water where he is as he can keep anything from livebearers and rainbows to rams and discus I never hear him talk about buffering the water to suit the fish

 

[Mint]

Ah, dang it, and it was so pretty! I figured that since he was such a well-known YouTuber and hadn’t, you know, been attacked by the YouTube comments, that the fish were good somehow…dang it.
Oh well, I’ll plan it some other way. Would the actual scaping still work for a betta sorority? It is a beautiful scape for plants, even if it would be hard to trim. Would Amazon Frogbit and Tiger Lily be enough cover for the top? Would the bettas be trapped and unable to breathe from the top if there were floating plants?