Congress decrees we must be fair. They do not decree the Armed Forces must win wars...

(and the Cynic in me says that shows... )

First, I note the Commission Chairman who I'm sure is a great guy, very intelligent and well meaning apparently has no actual combat experience and that he headed up the Air Material Command wherein I suspect a great deal of diversity is inherent. Did that effect things? Don't know but I suggest it will pose some harm to the overall credibility of the study.

Secondly, not to pick on ganulv but simply to remind:
One way to better exploit the pool would be by setting different standards for different groups.
I doubt that will pass the scrutiny of many in Congress unless the services can make a better case than they did for DOPMA / OPMS 21 and many other statutorily (or financial threat) imposed constraints designed to impose 'fairness' and 'merit.' The fact that war isn't fair doesn't enter the equation.
One could also explore what can be done to help bring members of different groups up to a single standard. At the level of the individual servicemember that might look like special treatment.
Not so much on that latter point, Congress tends to approve of that sort of special treatment. The problem with the approach is that it has historically led to a drop in standards to accommodate the 'needs' of some...

As Bob's World illustrated above. He's got it right; the services need to back off some things including some senior personages pet ideas, establish firm and logical standards across the force and stick to them. I believe Congress would support that approach IF the services would be logical and consistent instead of trying to often trying to bamboozle the Congroids to do it the service way...