About the bewildering variety of dress in Highland regiments, I have in front of me a photo of seven members of the Argyll & Sutherland Highlanders, posed together in 1999, and no two are dressed alike. The caption says "On the ramparts of Stirling Castle, Argylls display the variety of barrack and works dress to be seen around the RHQ on any day."

Here's how they're dressed

1) Glen, sky blue shirt, black belt with Argyll dress buckle, kilt, plain day sporran on metal chain, lovat hose.

2) Glen, camouflage shirt and pants

3) Glen, light olive shirt, camouflage pants

4) Glen, light khaki shirt, white belt with Argyll dress buckle, kilt, plain day sporran on dark leather belt, lovat hose.

5) TOS, light olive shirt, dark olive pants

6) as for man # 2 but has the collar of his light olive shirt sticking out over the collar of his camouflage shirt

7) Glen, light khaki shirt, white belt with Argyll dress buckle, tartan trousers (trews)

Another photo shows

8) Glen, light khaki shirt, white belt with Argyll dress buckle, kilt, Full Dress sporran, red & white hose, spats.

That doesn't even count the forms of No2 Dress with jacket (kilt form having plain sporran and lovat hose or full dress sporran and diced hose and spats) and No1 Dress, Mess Dress, jumpers/sweaters, etc.

By the way all the shirts in these photos have long sleeves and have been rolled up.

And, odd to American military, all of the shirts (sky blue, light khaki, light olive) are absolutely plain, having no badges or patches or pins of any sort on them. Sergeant rank stripes are worn on an armband (the British love these, cf the Captain's armband worn in football/soccer). Warrant Officers rank badges are worn on a leather wristband. (I can't tell if the camouflage shirts have patches on them.)