The Mautes were a monied family in a close-knit tribal society where respect, honor and the Koran are paramount.
Military spokesman Lieutenant Colonel Jo-Ar Herrera said the 'Maranao' clan, to which the Mautes belong, has a matriarchal tradition, and so their mother played a central role.
He said Farhana Maute, who according to the neighbor had furniture and used-car businesses, helped finance the group, and she drove recruitment and radicalization of local youths.
On Friday, she was stopped outside Marawi in a vehicle loaded with firearms and explosives and taken into custody. It was a major blow for the militants, according to Herrera, as she had been the "heart of the Maute organization".
A day previously, the brothers' father, an engineer, was arrested in Davao City, 250 km (155 miles) away.
When the Marawi siege began, several hundred militants were involved, including men from nations as far away as Morocco and Yemen. But most of the marauders, who took civilians as human shields and torched the town cathedral, were from four local groups allied to Islamic State, and in the lead were the Maute, military officials said.
According to Jones, the Maute group has "the smartest, best-educated and most sophisticated members" of all the pro-Islamic State outfits in the Philippines.
Samira Gutoc-Tomawis, a local civic leader who knows some of the Maute's extended family, said the brothers rely heavily on social media to recruit young followers and spread their "rigid and authoritarian" ideology.
"The Mautes are very active online. On YouTube, they upload their ideas" she said. "They are articulate, they are educated, they are idealistic."
The Maute family's neighbor, who requested anonymity for his own safety, said the group's fighters are fearless too.