Should I overlook the fact that there is no unity in my boyfriend’s family?

I’ve known my fiancé for almost 7 years now and we trying to get married but it hasn’t happened for various of reasons. But lately I’ve witnessed and seen how the dynamics in his side of the family are polar opposite to how I’ve been brought up. His family as a whole have trust issues. I truly believe none of them including my fiancé trust each other. There’s constant arguing, constant blame and no one takes responsibility or even likes to lift a finger but they quick to judge and comment on how someone should do it. This also extends to his uncles and aunties. If I were to be married into that family I will have no one on his side to support me or be there for me. Should I be concerned?

Just to add his sisters, brother and his parents all rely on my fiancé to deal with difficulties, whether that’ll be financial, looking after younger sister or looking after his parents care.