Not sure I'm following you. No war has started yet and I'm not sure who'd fight in that proxy war for Saudi's side. Sunnis in Lebanon are militarily irrelevant, Hezbollah is by far the strongest army there, much stronger than Lebanon's army itself who they pretty much control too. It could only be Israel who could fight against Lebanon's shiites but I wouldn't call that proxy war then.
Anyway, we're probably for some more utter shite on Middle East though. Saudis found themselves in pretty losing position last 10-15 years. Iran took over several Arab countries and Saudis are very nervous. Plus they're buddies now with Trump and Netanyahu and that's seriously bad combination of dickheads.