Who are the real losers when immature members gain rank too quickly?

Good question, the real losers are the ones that supervisors have not given accurate feedback or rating too and are allowed to promote too quickly. They are the losers because they are going to be challenged to lead and supervise as you say however at some point they are going to be held accountable for the responsibilities of the rank they are promoted too. When that happens it will have a huge impact on their career and mental state as they have to work though not being as "good" as they were led to believe they were.

Do their subordinates lose as well? Yes but their subordinates can always get mentored and developed by others around. It's easy to see through those that don't have a clue.

The ones that pay is the subordinate they will (attempt) to lead. You have to select the right Service Members, we grow our military ourselves, do the counseling, challenge your subordinates with tough, realistic training and reward them for demonstrated excellence.

TSgt Joshua Lynch, E5/E6 promotion will go to those with the best performance that test well. There will be a HUGE points advantage to those that receive the top definitely promote rating. That said, those that get the equivalent of the old "4" and "3" are still promotable, they just have to test even better. Once you get to testing for E7+ it really becomes about long term sustained performance since the board score is the largest chunk of the point.

For E7 specifically, there is a fee to get to the show, have to get that pair of 40's (aggregate of 90) and be in the top 60% to get to the board. For E8+, no CCAF means no testings.

All of these changes might just slow the "fast burners" who just "test really well" since the EPR weighs so heavily now.