Your argument suggests that you think Muslims should participate in wars based on sectarian alliances- "Hezbollah should not be expected to help Sunni Hamas because Hamas is Sunni" kind of thinking - but Iran doesnt operate strongly or solely based on sectarian lines, Iran is more strongly aligned around ideological alignments- Iran will work with any group if they share similar ideologies, goals, strategies and objectives that Iran has. But if you butcher Shiites, Iran will show up in and do something about it.
I think what he's saying is the Sunni faction of Islam needs to stand up and do something as well, as per his last sentence, "Hezbollah is doing what it can." It would be suicide to drag Lebanon itself without the support of the other bigger parties in the Arab World. Remember, Lebanon is open like Gaza if Israel decides to do relentless bombing.