We've been having trouble lately with players selling powerful decks to low level accounts and going crazy in the 5-12 rooms. We've got some adjustments in the works to help prevent this but until we ship them we've changed the fight type 1 & 2 rooms so that they are all level 7+. Not a perfect solution but it will allow for a more balanced group pf players where the strong will have less chance to prey on the new players with no real opposition.
It is better than nothing but in my humble opinion why not make a restriction in the level of player that can play in a daily tournament like in ELO.
Sending new players in to the wild just after they were born in game makes them easy prey for experience players who knows and like to abuse the system.