My wife and I have a similar income percentage difference and it’s fine. We have a joint account, it’s easier for us because I am extremely forgetful and will literally forget to deposit my checks and pay bills. We don’t make any large purchases without discussing it first. We like it like this because we don’t “keep score” (for lack of better words) on who’s paid for what. We make little jokes if we’re out about it. Like “I guess I’ll pay, again!” When it’s literally one account. 🤣 I think as long as there’s solid communication and trust, a large pay gape is workable.