Definitely. Bruce Banner's transformation into the Hulk was the starting point of the entire concept. The comic storylines have always centered around this original transformation and its consequences.
Bruce Banner became the Hulk after a catastrophic gamma radiation incident during one of his experiments. The radiation altered his genetic makeup, causing him to turn into the Hulk whenever his emotional state becomes intense, mainly anger.
Sure, She-Hulk is related to Hulk. Jennifer Walters, aka She-Hulk, got her powers because of a blood transfusion from her cousin Bruce Banner, who is Hulk. This connection is a key part of their storylines in the comics.
Captain America would be a great addition. His leadership and moral compass could guide Hulk and She - Hulk when they face difficult decisions. And his combat skills could come in handy during battles.
Comics usually depict Hulk as stronger than She-Hulk. Hulk's strength levels are often at a much higher magnitude, but it doesn't mean She-Hulk is weak by any means. She has her moments and skills that contribute to her being a significant character in the comic universe.