Gordon Adams sees  real problems in having at least two and possibly more ex-generals in key national security positions:
The fundamental bias — and a necessary bias — of trained officers is to create a military and to advise civilians about the contribution of that military to national security policy. It is a military mindset, a necessary part of their professional expertise, and borne of years of training and education. But it is not a balanced view of how the United States should engage the world. As such, the military paradigm is likely to be the dominant narrative, to the detriment of broader thinking about statecraft. That paradigm focuses on solutions to tactical and strategic problems but not on the nuances of managing intractable international issues.
U.S. foreign policy has already become overly militarized during the last fifteen years of warfare, and there is already a very strong bias in favor of (military) action in our policy debates, so it is fair to be concerned that putting former generals in major policymaking roles can only reinforce both. The problem is not that they will necessarily make the U.S. more likely to take military action in each instance, but that they will tend to view all crises and conflicts through the lens that they have been trained to use. The U.S. already gives short shrift to and spends comparatively little on non-military responses to problems overseas, and putting former generals in top positions makes it likely that this won’t change for the better. This is especially true when one of the former generals in question believes  that the U.S. is engaged  in a “global war”  that will last decades and another has a decades-long grudge  against another state.
Generals — even retired ones — should advise, not make policy. A successful national security policy depends on restoring the civil-military balance that has been lost in the lopsided approach of the last 15 years, one that has clearly failed to the detriment of U.S. security. Our civilian national security institutions need reinforcement to help restore that balance; but with two generals in place and a possible third to come, it is very late in the day to restore this important equity.