* Gale and Peeta represent different parts of Katniss' life: Gale represents her life in District 12, her childhood, her family, and her survival instincts. Peeta represents the Games, the Capitol, and the possibility of a different life, one filled with love and safety. These two sides of Katniss' world are in constant conflict, making it difficult for her to fully embrace either one.
* Katniss' feelings are complex: She feels a deep connection to Gale, a shared history and understanding. They understand the harsh realities of their world and are fiercely protective of each other. However, Katniss also finds herself drawn to Peeta's kindness, his ability to inspire hope, and his genuine love for her.
* The Games create a pressure cooker: The Games force Katniss to make difficult choices that impact her relationships. Her actions in the Games create a divide between her and Gale, who feels she's choosing Peeta over him.
* Katniss' survival instincts: Katniss is fiercely independent and protective of those she loves. This clashes with Peeta's more trusting nature, which makes it difficult for her to fully open up to him.
Therefore, it's not that Gale and Peeta don't coexist well in Katniss' thoughts; it's that they represent conflicting sides of her personality and experience. She struggles with the emotional tug-of-war between these two men and her own conflicting feelings. It's this internal conflict that drives much of the emotional tension in the story.