This is not a distributive negotiation. This is a complex compound negotiation. I believe in reality the defence agreement has only 2 concrete elements.
1) Shared Nuclear Deterence (at some stage may become part of Pakistans second strike capability) .
2) Capacity building ( Skill for Saudi and finances plus material/strategic resources for Pakistan)
A possible 3rd soft element is soft political deterence.
The reason the treaty has gotten a lot more attention than it should is because it can be tie breaker thay decides which direction Paksitan takes if it comes out of non aligned mode.
Somehow there are factions that feel threatened in both directions ( Iran Vs GCC). It would be wise for us to give reassurance to our own that as a Pakistani, regardless of which country rhe state strategically allies with, the onus of safeguarding the common Pakistani and shielding them from any toxic side effect of these alliances is on us. Both as a government and as a society. Ego is an Achilles heel for us, but in this matter ghairat should be a unique strength.
The elephant in the room is simply this. Each faction fears losing its rights in Pakistan society from the influence of a foreigner partner who hates them hence they malign these opportunities. We really have to elevate the sanctity of our own citizens. If we are aligning with a particular foreign partnerz because it is the better deal for us, internally we must work twice as hard to protect those of our compatriots who those foreign powers work against.