unfortunately, the answer is:
it all depends.....
it depends on what the originator of the recipe intended, though IMHO, most recipes seem to go for a pretty standard amount, say 2 or 3 pods per dish for 4 people.
it also depends on the pods you are using, how old it is, where it was grown, variety etc. The amount of essential oil content varies, and the amount of each component in that essential oil can vary. It really is up to the cook to adjust to taste.
If you found it about right, for me, thats the best indicator. Note that aromas, by their very nature, are volatile, so how you cook it, and for how long, and whether you use a lid, etc., will all have an affect.
However, one big difference is due to when you add it to the dish. The main flavour component in green cardamom is a chemical called 1,8-cineol, better known as eucalytol. It is (nearly) a pure hydrocarbon, and dissolves in oil in preference to water. If you add the cardamom to the dish at the beginning of cooking, the flavours stand a much better chance of entering the oil/ghee than if you added the spice after water-based ingredients were added. Adding a sprinkling of powder at the end of cooking (like the modern craze for adding garam masala powder) will produce a different result, and may well unbalance the dish, flavour-wise.
HTH
cheers
Waaza