At first, the answer to this question might seem rather apparent. If the characters changed or never existed then of course the book would be different. A book—whether it’s Mean Spirit or otherwise—is determined by the composition and presence of its characters. If the characters are altered or done away with, it makes sense to conclude that the overall book must either fundamentally change or never appear in the first place.
However, when taking into account the context of Mean Spirit, an alternate answer develops. Linda Hogan’s novel is based on real events. In the 1920s, the members of Oklahoma’s Osage tribe were targeted and killed because certain white people wanted to acquire the oil that was in their land. Due to the complicity of local and state law enforcement agencies, the violence continued and the murderers remained unpunished.
Considering this history, one can reasonably argue that even if the characters were different or didn’t exist, something similar would’ve happened. After all, the deadly persecution suffered by the Osage tribe wasn’t based on the personal character traits of any one individual or even a group of individuals; it was systemic. There was a prejudiced foundation in place that made it possible for white people to treat the Osage not as people but as obstructions to wealth and prosperity. Thus, Mean Spirit could feasibly happen with characters other than Grace, Nola, Rena, and so on, because, to the nefarious white people who carried out the murders and violence, the Osage people were basically interchangeable.