I think Duke adding LEDs has nothing to do with fairness of the game.
No one specify that contestant cannot add or remove their light as liong as they stay within the say technology, no one seems to have defined that they are comparing their current setups anyway. For e.g., if one of you guys(say the MH guy) has a bulb burnt or exploded due to splash, and I think the other contestants are not going to forbid him from changing the bulb. As for Duke to add LED to the front or back to a corner tank seems very logical which he should have done in the first place because LED is angular and thus having frag rack up too high is not a proper placement anyway. It seems the game is about how you can grow with LED, T5 and MH and win out the others but not current setup 1 vs current setup 2 vs current setup 3. Therefore, if anyone want to add 2 to 20 bulbs and think that's optimal to his tank, I think all contestants will welcome the change.
Actually by the time you guys finish, may be we have Jerl, Duke and James designer acros. LOL