The Saudis are the strongest they've ever been, have the support of a powerful regional alliance and active military assistance from the USA.
The Iranians are the most vulnerable they've been in decades, and have no reliable allies.
But they are still within a decade of acquiring nukes if they decide to push on with that. They've got more reason than ever to do so now; Trump is openly attempting to destroy the Iran treaty, and has already violated it on the US's side. Nukes may be Iran's only chance of survival.
In return, the Saudis are very aware that their opportunity to defeat Iran may be slipping away.
The Saudi military are not a pack of untrained tribal militia these days. They're likely to have issues with command quality, and morale may be unreliable if things go bad (both standard features of corrupt totalitarian states), but in raw firepower terms they're a significant player. F-15s, Abrams, Bradleys, Apaches, all in large numbers and backed by shitloads of infantry. The Iranians have comparable manpower, but technology that is a generation behind: Phantoms, Mirages, ancient F-14s and M-60 clones for tanks.
That "largest ever" $60bn sale in 2010 has since been followed by this: