For hipfire 360 distance is a perfectly viable option, and it might even be for ADS if it doesn't zoom too much.
Matching FOV is the best way to get an identical sensitivity, but it isn't possible in all games. For those where it's not possible you have to choose which method to use as you can only match one aspect of the sensitivity. There is not one method that is best however, it depends on what you prefer.
For higher power scopes however you need to use another method, which one depends on your preference.