The more boxes/cards they release into this game, the more luck based DL will get due to complete random PVP matchups and limited field space. If anything, Konami should update Ranked Duels and give everyone an extra magic/trap/monster slot.
Actually it is random and luck. Even with 20 card decks and 4 card draws, you can get a bad combination of 4 cards that will cripple your start to the duel.