I think they should put Betsy in the Avengers to dampen Bruce's compulsive macabre: they could just take the damn green she hulk story, turn her red, and most of the film watching populace would never know the difference. Would it be a shame to not see green she-hulk? Yes. But frankly it would just be nice if Banner had someone he could recognize as a similar victim, but one that saw the scenario in a positive light. Also...red she-hulk...who doesn't want to see that?