If I understand correctly, you are referring to the fact that the cam pulleys have a small amount of advance/retard adjustment, but there is no marking indicating the correct position?
What you have done sounds fine to me, and it is probably the best way to get the pulley as close to the original position as possible without special tools.
If you had them way off the engine might run poorly, or just differently. If you haven't noticed anything then it's fine 👌
