In Dragonball GT, why were there only 7 shadow dragons if there was definitely more than 7 wishes made?

They(writers and creators) made the dragons appear from the most memorable wishes and also they want the number of dragons to represent the number of so they could have the dragons separate like the dragon after wishes. Don't u reckon Syn Shenron looked weird? He was so weird. well i didn't like him. He looked worse on the game.