I love the special events and I love golf. Seem totally unrelated but please read on for a moment.
The beauty of golf is if you have a handicap (-strokes from your total score) you can compete against someone that has a handicap. That evens the playing field.
Now, back to empires and puzzles.
The special events are awesome. One complaint I have seen is the rich get richer. Which is true.
Keep the gross score, but add a second score, net. Net would equal overall score divided by team power for each level. This would allow younger players to feel a sense of accomplishment. You may not be the best, but you played it extremely well.