But KSA has no ambitions towards becoming a global military superpower. For a long time it had a choke point on the economy through its resource monopoly. Until recently that was a much more potent weapon than any number of aircraft carriers.
Russia does have superpower ambitions, which is a rather more expensive business.
My cynical suspicion is that much of the KSA military budget is really just a form of kickback - or possibly protection money, depending how you look at it - to the US mil-ind establishment.
While the Saudis are some of the worst people in the world, their ambitions are limited to keeping the ruling dynasty outrageously rich and maintaining power on their own patch of turf.
The Russian establishment is far more dangerous. It not only has links to organised crime, it also has a complement of nukes, bio, and chem weapons. And it has a very developed infowar, hacking, and social destabilisation arm, based on techniques pioneered by the US, with some home-grown twists to increase effectiveness.
This oil war and related COVID crash are going to do huge damage to the economies of both countries - and a lot of others besides - with increased prospects for instability everywhere.