Dunno about you guys but the big killer is the gear that you wear in combat. Fine you can run a 5k, but can you stand in your helmet, body armor, combat load of ammo, radio, grenades, rifle, etc etc etc etc for 18 hours at a time. Better yet hump a good 10-15 k of that? I DOthink a 5k would be a good measuring stick to see if you can do that.
The army was kind of strange, they stuck to the APFT, but every commander knew that company runs and training needed to be in body armor with gear, because that is the only way you are going to get used to it.
Got no recommendations, just something to think about. You aviators probably understand that kind of thing well because of the types of maneuvers you endure and I know the Marines were PTing with body armor before it was even cool.
It just seems that there are two schools of thought on physical fitness:
ONE make physical training similar to combat
or
TWO maintain PT standards to ensure health and overall wellness/discipline standards
maybe the Marines have it right with this new idea:
i'm just waiting for them to add the high speed torso burrito to that new PFT (CFT)