Really, the more they deviate from the core rules, the more they need to adjust and alter things because of all the consequences of their homebrewing choices. They really ought to FIRST try and make things very true to the rules and get that working before they alter things, since there are numerous things they couldn't foresee and now they have to change because of their modifications. All the new classes and everything that they are yet to implement will likely be quite different from the core rules.
