Yeah kind of, the wattage or joules needs to be enough to allow the coil to heat up to your desired temperature under your vaping conditions, as whilst the wattage you apply is heating it, the air that you are drawing over the coil is also cooling it down at the same time. So the more cooling you are applying then the more wattage you will need to acheive your desired temperature.
For example, reaching 400F in a kayfun will require alot less wattage than in a sub tank as the sub tank has alot more cooling than the kayfun.
Its a balancing act between heating / cooling and how warm you like your vapor to be on a given atty and with a given coil to find the sweet spot for you.