The Ties that Bind: Families, Clans, and Hizballah’s Military Effectiveness

There is a relatively simple explanation for why Hezbollah often has a succession of martyrs and fighters from one town or clan: money.
Their Clan Leaders view supplying fighters as a revenue stream - aka a Iranian version of the Anbar Awakening. So long as it remains lucrative for them, they will continue to send lesser-born relatives to fight in Lebanon, Syria, or Israel. Religious fervor and martial glory are just the opium they have these young men smoke to convince them it is a great idea to blow themselves up.

Follow the money. It almost always leads to motives for why people do what they do.