Learn English – Two things which can go together

There are several words that apply here. The soup with the heavy stuff on the bottom and liquid at the top is in an equilibrium or a steady state. Sometimes, when you perturb an equilibrium, then remove the outside influence that was changing things, the system returns to its old steady state. So if you push a swing or a pendulum, just once, it will wave back and forth for a while and then eventually settle to hanging straight down as before. You stir the soup, it gets all mixed up, then you stop and it goes back to how it was.

But not all properties of a system depend only on their current state. In high school chemistry we learned that the viscosity (thickness or runniness) of, say, water, depends only on its current temperature - you can freeze and melt, freeze and melt, but 50 degree water will always have the same viscosity. Not true of an egg: if you boil it for ten minutes and return it to room temperature its viscosity is permanently changed.

And some systems return to a different equilibrium after a perturbance. Consider a piece of paper or wood. If you apply a little heat to it (say, a match) then it goes from being stable and just sitting around to burning. And it will happily continue to burn although the match is gone. In many cases when it has stopped burning the equilibrium it reaches is being a pile of ash and cinders. Or a burning piece of wood, if you blow on it to blow out the flame, won't go back to burning when you stop blowing on it.

In physics, you use the word elastic to mean that the shape changes with stress, then goes back to the old shape. (This is what an elastic band does.) The word plastic means that it changes its shape and stays changed, like plasticine or playdough. But if you want to use these metaphorically, tread carefully, because most people take elastic to mean "can be stretched indefinitely" and forget the part about going back to the old shape when the stress is removed. To use some more words from physics, resilient is popular for recovering back to the old state, and brittle for not doing so, like your smashed computer. And when you build a computer, you are removing a lot of entropy, getting it all ordered and carefully arranged. But in the absence of outside forces, entropy only increases. That's why the smashed computer won't go back to how it was.

Once you bring in the cows/grass example you are into predator-prey theory and not far from chaos theory, full of crazy words like saddles and strudels. There are stable equilibria, unstable equilibria, and all manner of words that mean a lot to practitioners but less in general conversation. I think your best bet is to describe one state of a system as a stable equilibrium while understanding that when you're being precise, an equilibrium can be stable to some perturbations (like stirring) but not to others (like being poured down the sink or being eaten.)

It sounds as though you are trying to write about the difference between wealth and nobility.

One who is poor financially is in poverty, or economically destitute, or bankrupt, though the last one is also a technical term. One who is poor in ethical qualities could be called inethical, immoral, abhorrent, crude, or any other number of words to describe one who is poorly-behaved. VERY specifically, if it is someone who doesn't share their money, you could say they are "cheap" or "a miser" or, more kindly, a "spendthrift" if they always spend as little as possible on their ventures.

Metaphorically, one who has no moral guidance or standards can also be called 'Bankrupt', though usually it is specifically called 'morally bankrupt' - meaning this would be two words, not one.

Financial richness has quite a few terms to describe it: wealthy, well-off, well-to-do, or one could be a millionaire, billionaire, or even trillionaire (All three being categorical). Whereas being rich in an ethical sense would be honorable, noble, decent, kind-hearted, and willing to share wealth would be generous, philanthropic/philanthropist, and charitable.

I believe the term you're looking to use depends on the exact nature you are trying to express in the person you're describing. Are they very willing to offer their wealth, even if they have little? Are they individuals who are incredibly wealthy, but who refuse to hand out their wealth? Or is it the grace of the person that you are judging? As in a poor individual who acts with dignity, or a wealthy individual who acts very cruel?

There is certainly a multitude of metaphors connecting wealth with virtue. Even "noble" has the connotation of being one of a higher-class and, therefore, wealthier than others (though this is a connotation, and in actuality nobles are not always wealthy). Rich in virtue, poor in manners, there's quite a lot of ways you can phrase what you want to say.