When can I use a pronoun in place of a prepositional phrase?

[capet]

I understand that there may not be a rule, I'm just trying to understand.

f I understand correctly, this video shows an example of replacing a prepositional phrase with a pronoun. It pretty much says that these two sentences are equivalent:

• Mi hermano prepara la sopa para nosotros.
• Mi hermano nos la prepara.

That makes sense to me.

So now I'm trying to understand when I can replace a prepositional phrase with a pronoun, and when I can't. Can you help me understand this?

For example, I think the following two sentences are correct:

1. En estas circunstancias la comunidad exige este derecho.
2. Luchamos contra el yanqui.

However, I'm not sure whether the following (or anything similar) are correct. (They both feel wrong to me.)

1. La comunidad se lo exige.
2. Le luchamos.

I think that there is a similar issue in English: I can say "I gave a bath to the dog" and "I gave him a bath," and I can say "I lost the battle despite my courage," but I can't say "I lost it [my courage] the battle." In English, I resolve this by looking for "to/for vibes," but I don't know whether that's even correct for English. I mostly rely on habit, and I don't have Spanish habits yet. I don't want to rely on trying to directly translate Spanish prepositions into English; many sources warn me against that!

Here's why I've been having trouble with this: I've seen many examples of a pronoun replacing a prepositional phrase beginning with "a," and I've seen a few examples of a pronoun replacing a prepositional phrase beginning with "para." But I cannot find any rules or guidelines for whether I can do this or not. Some people have told me that I can do this only with indirect objects. Some people have told me that "nosotros" in the above example is an indirect object, other people have told me that it can only be an indirect object if it is preceded by "a." But it the "a-only" people are correct, then "nosotoros" above must not be an indirect object, so then sometimes I can use indirect object pronouns to replace prepositional phrases that do not contain indirect objects! On the other hand, if the "a-only" people are correct, then I don't know how to recognize an indirect object. It seems like the "vibes" around that are different in different languages. For example, in English, I would not consider "basket" to be an indirect object in the sentence "throw the ball at the basket," because I would not say "throw it the ball" to mean "throw the ball at the basket." But in Spanish, I think "canasta" is an indirect object in the sentence "lanza el balón a la canasta." Assuming I'm correct about that, it is not at all weird that different languages would treat this differently. But it means that I cannot continue to rely on "English vibes" to determine which prepositional phrases can be replaced by pronouns!