I think with fixed allocation, people get much higher tokens than that of stake based system in a sense that if say, in a signature campaign of stakes from member to legendary as 1, 2, 10, 20 and 30 respectively, a legendary member that join for just 2 weeks gets much higher total stake than that of a member who even does for 30 weeks. Suppose it were a fixed allocation, one does not care about the higher ranks that join later to make the coin distribution skewed to higher staked ranks.
If it's gonna be a fixed allocation, we can still expect that higher rank will receive a better pay compared to the lower rank, that's the norm here.
The advantage of the high rank if they join a signature campaign is they can wait and see if the project is close to success then they can join even in the last stage of the campaign.
other managers are making capping the number of participants which is a good idea, usually, they cap to 150 to 200 participants in the campaign, so this will prevent from those high rank who are taking advantage to join in the later period.