Why were the phrases "his people" used with our master Noah and "their brother" with our master Hud in the Holy Quran, and what is the significance of each?

The messengers are usually mentioned after their people, but the people of Noah, Abraham, and Lot did not have a specific name; they were known by their messenger. As for the people of Shu'aib, Hud, and Salih, they had a known lineage. The meaning of "their brother" is that he was from them by lineage or their companion. The description of "brotherhood" was mentioned for Noah (peace be upon him) with his people in Surat Ash-Shu'ara, just as it was mentioned for the other prophets (Hud, Salih, Lot) in the same Surah (definition). The only difference is with the Companions of Al-Aykah, where Shu'aib was mentioned without the description "their brother." Scholars differed on whether they were one nation with Midian or two nations. The preponderant view is that they were one nation, and the difference in description is due to the context. In "Midian," Shu'aib was mentioned as their brother by lineage, while in "the Companions of Al-Aykah," this was not mentioned because he addressed them in the context of their polytheism and worship of others besides Allah.