@JTam Hold it right there brother, a certain U.S. Air Force Senior Master Sergeant may care to disagree about the Air Force using chinstraps on their boonie caps...
https://commons.wikimedia.org/wiki/File:U.S._Air_Force_Senior_Master_Sgt._Leonard_Arsenault,_with_the_11th_Security_Forces_Group,_acts_as_road_guard_during_a_ruck_march_Sept_120911-F-MG591-003.jpg

Joke aside, I fully expected someone to post a photo of some American Soldier/Sailor/Airman/Marine in a boonie with a chinstrap cinched up under their chin. I am sure someone does but I just do not recall ever seeing it so it jars for me. Jars... heads...Marines...... see what I did there? The jokes just keep on coming....
As for the backwards cap, yeah that irks me too but it will make for a good PMC head I suppose....... or perhaps an operator operating operationally....
At least the caps are not too big and pulled down over their ears/back of their head with flat, uncurled brims.
Some interesting info on boonies...
https://www.propper.com/blog/the-history-of-boonie-hats-in-the-us-military
When in doubt, refer to AR 670-10?
From the above link....
Today, OCP boonie hats are standard for the U.S. military when patrol caps and helmets are not being worn. For example, the Guide to the Wear and Appearance of Army Uniforms and Insignia specifically states in section 4-10:
“d. Sun (boonie) hat. The sun hat is an OCIE item authorized for wear with the combat uniform in field environments when the advanced combat helmet is not worn, on work details, or in other environments where wearing the patrol cap is impractical, as determined by the commander. Personnel wear the sun hat straight on the head so that the web band creates a straight line around the head, parallel to the ground. The sun hat will fit comfortably around the largest part of the head without distortion or excessive gaps. The sun hat is worn so that no hair is visible on the forehead beneath the hat. The draw string on the sun hat can be worn under the chin, around the back of the head and neck, or tucked inside. The drawstring will not be worn over the top of the sun hat. The sun hat will not be worn rolled, formed, shaped, blocked, or with an upturned brim. Subdued pin-on or sew-on grade insignia, or branch insignia for chaplains, is worn centered on the front of the headgear left to right, and top to bottom (see para 19–3e).”
https://www.usamm.com/blogs/news/the-history-of-boonie-hats-in-the-u-s-military

I never wore a boonie while serving... but I did wear a blocked and curled BDU cap which would probably be frowned on in some units of today’s US Army and I would have curled the brim on the bearded cap wearing head.
I can see several of the heads being better for Cops than Soldiers/Marines. At first I was not a fan of the rolled up sleeves but they have grown on me and while I was not allowed to wear fingerless gloves in my time in the US Army I did get away with it while attached to the British Army Royal Welch Fusiliers in the early 90’s.