That problem though, can be more easily solved by assigning experience based on the challenge of enemies, so level 1 peasants and rats offer chump change, and the level 4 Silent Monks 700 XP will also likely be toned down a bit because they do not offer much challenge because they're always fought 4 on 1.
This sounds good to me.
Giving exponentially more XP for higher level enemies and requiring exponentially more XP for each additional level would accomplish the same thing.
Another option would be to scale enemies and rewards with player level in the effort that things will continue to be rewarding and challenging regardless of previous choices. But this is a very divisive idea whenever it is used.
Edit: I love exploring everything and doing all the quests, but dislike it when over-leveling encounters makes them too easy. A system allowing me to have both sounds great!
