No. There do indeed exist sufficiently grave reasons why a civil ceremony can either precede or succeed a religious ceremony (e.g., in countries where priests do not have the authority to sign state marriage licenses, a civil ceremony may be necessary to assure legal civil validity for the marriage). Simply wanting a particular guest present for your wedding is not a sufficiently grave reason. However disappointed you undoubtedly will be not to have your brother present at your wedding, his presence is not strictly necessary and certainly isn’t reason to have two ceremonies. If you want your brother to participate in your marriage celebration, then have your religious ceremony as scheduled and delay the reception (i.e., the party that celebrates and honors the marriage) until his return.
