Is it permissible for the questioner's brothers to marry their maternal aunts' daughters, given that the questioner's grandmother (mother's mother) breastfed his eldest brother?

If the elder brother suckles from the grandmother (mother's mother), then he becomes a foster brother to her daughters and a maternal uncle to their daughters. It is forbidden for him to marry any of these girls, due to the Prophet's (peace and blessings be upon him) saying: "What is prohibited by lineage is also prohibited by fosterage." As for the rest of the brothers, it is permissible for them to marry their maternal aunts' daughters, as there is no impediment.