I think they will definitely slow down the progress either by lowering the xp/credits gain or increasing xp/credist requirements because the progress is just too fast at the moment. For example I have 100 games played so far with 50% win, all with standard account, and I unlocked 1 tier 6 and 3 tier 5 ships. With that amount of battles in World of Tanks you would only get one tier 5, especially as a new player.