Konnichiwa zeroh4nter-san!
I can't properly answer your question because I don't know the details of the story. I'm just answering your questions about Japanese language.
Yes, "戦う場を作れた" means " I/we have created a battlefield" in literal. This translation is correct.
By the way, "場を作る" has a different meaning from "make/create".
example.
"私は会見の場を作るために汗を流した"
I worked hard to arrange the venue for the meeting.
In this case, it means not only arranging the venue, but also various other preparations such as coordinating schedules and arranging transportation and etc....
If the following two sentences have the same meaning, your translation is perfect.
"I worked hard to create the venue for the meeting."
and
"I worked hard to arrange the venue for the meeting."
"作る" has many meanings, create, make, build, prepare, set up and etc...
Which word do you think is appropriate? Sorry, I'm good at Japanese, but I'm not good at English. And I don't know the details of the story. Therefore, I cannot answer any questions about the interpretation of the story.
Furthermore, as an idiom, "場を設ける" is more common than "場を作る". Both phrases have the same meaning, but in Japanese, the correct usage of the phrase is "場を設ける".
This also applies to the example sentence. "私は会見の場を設けるために汗を流した" is more appropriate.
Based on the first question, "戦の舞台を設ける" would be a very literary expression more than "戦う場を作る".
The reading of "戦" is "いくさ:Ikusa". "戦:Ikusa" and "戦い:Tatakai" have the same meaning, but "戦" is used as an older expression.
This explanation(設ける and 戦) has nothing to do with the original question. But if you want to learn Japanese, this explanation might come in handy someday.
NANGI