Dual primary regulator

I have two primary regulators connected together at the tank. This is different than using a secondary regulator, right? My understanding is that primaries are "higher pressure" vs secondaries which are "lower pressure".

I have heard that if you use secondary regulators that the pressure in the primary has to be higher than the secondary. For example if your primary is 35psi than your secondary would be anything lower than this.

But how about if you have 2 primaries connected - does it matter? Can the pressure in the 2nd regulator (the one farthest from the tank) be higher than the 1st regulator (closet to the tank)?

This has always confused me.

With two primaries the pressure going in to each is tank pressure, so it doesn't matter which one is higher pressure. With a primary and secondaries, the primary has to be as high or higher than the secondaries, because it is supplying the gas to them.

I have a pair of Micromatic primary regs hooked together...its great, like rodd said, set them to whatever pressure you want.