Smok mods detect the resistance (ohm) of your coil automatically. Compared to other brands sigelei for example, smok does not have a separate menu/system button for that, or I haven't found it yet lol. So every time you screw your Atty on the mod it will ask you new/old coil if you made changes, then you can hit yes or no.
Ohms do differ depending on battery life/mod/used prior/dry burnt/material itself when heated or at room temperature, gunked up etc.
However, its mostly just a difference of max .2. What you're describing makes me ask the following question. Are you trying to run a dual coil build or single? Because if you're trying to do dual coil setup, the ohms divide by 2. The description of your pre made coils is for single builds. Here's a good site
http://steam-engine.org , that most of us recommend when building your own coils or using pre mares in a build deck.
So make sure, if not building on a 510 stand or an ohm meter, but using your own mod to remove the Atty from the mod itself, and put it back on after installing new coils, even if its the same ones or just have been cleaned, to get an accurate reading before firing/dry burning it. Hope it helps.