It exists already! It's called "other classes".
Kidding aside, if somebody doesn't like the way a Warden is played mechanically, they shouldn't play one. I don't like classes with reactive skills, so I don't play one of those.
Remembering Gambits is just a part of the Warden difficulty. Traiting right, using the right gambits for the situation, reacting to changing conditions, balancing gear for the task at hand, selecting the right legacies, &c. are also parts of the whole picture. I've seen Wardens fail at each one of those steps.