A long time ago, around 2011, I was still a hardcore RO fan who played WoW on the side. I used to mock WoW because the only way for them to stay interesting is by overhauling their classes at each expansion. Basically relearning how to play at each expansion. Now as a more mature adult, I realized that their system had its merits. Most important of all is how they are quick to address class/skill concepts that must have looked good in concept, but didn't pan out in the game.
Now let me relate this back to RO with these new 4th classes. I hope whatever concept skill builds and play styles they come up with, they will be quick to address or even outright change things that clearly don't work from the start. Just to give an example when 3rd classes were brand spanking new, "Spell Fist" sounded amazing for those who loved to play Hindsight Scholar. It didn't take more than a few weeks in for players to realize how utterly garbage it was mainly because it took too much effort to activate it for a mere 5 hits. Now several years later with the 4th class announcement, they finally realized to do something about it. They're a little too late there.
That's just one specific example. Honestly, look at the recent 2nd and trans class skill balance we got. Honestly, more than half of those things would have been amazingly wonderful to have at the height of the trans class era. And it isn't until we're way past that point before they started going back on those now "old" skills and fixing what was fundamentally wrong with them in the first place.