KSA suck at politics and geopolitics. They have seriously no real understanding of the threats and issues and how to proactively counter them, all that oil money has bought them lots of fat on brain cells.Pakistan can milk the heck out of KSA about this issue, lol.
In reality, Pakistan has its own Geo-political aims that it needs to follow, such as CPEC Gawadar and China is involved fully in it. In case of Chabahar, China itself is not much concerned. China will not damage its relations with Iran unless Chabahar poses a threat. Its better if Pakistan does not involve Russia in any issues with Iran. Pakistan should infact involve USA and make some deals with Israel ideally, but then again lets wait and see what IK does. As for Pakistan Military, they wouldnt want a new front opened with Iran. They would rather build a wall, install posts and end the cross border movement.
Pakistan's problem is how to effectively neuter the domestic inclination towards and affiliation with Iran. China after Gawadar and CPEC becomes a party to any conflict that happens in Balochistan, but then again any harm to their interests can bring a lot of disruption in our relations with them.