Not specifically mentioning Bleed Nipples here, Generally speaking regarding how tight Fasteners need to be, what's needed is not the Torque applied to it, but the amount of Stretch (or in some instances, compression) over the length of the Fastener between the 2 points where it's being held by, eg a head stud in the block is held one end in the block and the other by the nut. It's the Stretch of the fastener that does the job of holding - clamping - the parts together under the required pressure, just like a G Clamp.
The Torquing of Fasteners in General using a Torque Wrench, when you break it down, the Re-active Torque or effort needed on a fastener by Torque is a combination of stretching the fastener by holding one end fast, then pulling on the other end by dragging it up a ramp (ie, the Thread) and the Friction of both these Threads running against each other and between the back-side of the fastener head and the part that under it.
The Stretch can easily and accurately be calculated by the angle of the Ramp (the Pitch of the Thread), however, the Frictional values are quite variable and more so when dry of any lubricant. The Threads might be nicely rolled formed in materials that respond well to that process, or cut in to Cast Iron by Tapping. Each of these will have very different frictional values. Another factor here is the type of finish applied to the fastener (and how well that's been done), eg plain steel vs galvanised. The Finish and Hardness of the Surfaces of the underside of the Fastener and the Part can equally be quite variable, particularly when dry. Torquing and undoing then Retoquing again for about 5 or 6 cycles may 'bed' the parts to each other and so reduce the variation in fastener stretch, but it will still have a high variation between 2 identical fasteners.
According to ARP, and Unbrako Torquing Dry can have a variability as much as 50%. Most fastener manufacturers how have Torquing Charts are mostly Oiled numbers.
Coming back a bit to out Minis, all the Engine & Gearbox fasteners are Oiled numbers. The Suspension and Brakes I'm not 100% sure of, but they'd likely be Dry numbers. It would be handy if they included all this info with the various charts !