its not a stupid question, many people have different views on this, i am going to plant my new tank(in 3 weeks) "dry" which is without the water, this way i can get the plans closer together and think it will be easier overall, basically the only thing that can go wrong with this method is when putting the water in, the plants come up, however if you do not distrub the substrate and use like a plate when filling it is usually fine. its up to you