Is the marriage contract considered valid if the existence of the grandfather was denied to the court and the girl's brother was appointed as her guardian, due to family disputes and fear of problems?

It appears that the marriage contract is valid, and lying to the court does not affect its validity, because it is a marriage in which the conditions for validity have been met. According to the Maliki school, the brother has precedence over the grandfather in the guardianship of marriage. One of the objectives of Sharia is to validate contracts whenever possible.