My thinking on the difference in ponds versus tanks is based on why and how I look at ponds versus why I look at tanks.
A pond is an area where I look at the overall scene and a few fish like large Koi add to that scene. With large fish , there will often be some of them darting in and out or begging for food.
In a tank, we rarely have large fish like Koi but we do stop to look at the fish as we can see them well through the sides and they can see us so that they become less prone to hiding.
Since your tank plan will not support a group of large Koi, my concern is that the normal size tank fish will be very difficult to spot. For a place to grow plants that extend above the water, I would think this would work but for a fish tank to view fish, I would not bother.
Your views are free to differ of course but I just see a lot of work for a poor end result.