The Rhodesians made an art of combat tracking, Michael Yon says:
The Rhodesians would get on track, often simply by flying in helicopters and looking for it in grass or other opportune traps, especially during morning or evening patrols. You simply cannot move through many sorts of grass without making a color change.
You can try to hide track from air observation, and it can help, but that wastes time in the open. If numerous men go single file, there is no way to hide it. If they spread out, they leave more trails. Real accounts of combat tracking against good anti-trackers sound like a Tom Clancy submarine story. The submarines cannot see each other, but they can sense each other through various means. Even the stealthiest submarine creates disturbance.
After track is confirmed, the commander will have options. He can use a helicopter to put a dog down. The dog goes alone. The handler stays in the helicopter and controls her by the radio on her back. Rhodesians tried this and it worked.
They just put the dogs down on known track, and the helicopter lifted off to follow the dog. Many dogs love to ride in helicopters just like they love to ride in cars. If she gets tired of tracking, she might look up and bark at the helicopter. No matter where it lands, there she comes.
A Rhodesian account in the book Winds of Destruction mentions a dog inserted by helicopter. During training, the dog could track an eight-hour-old trail, more than nine miles, in 40 minutes. The dog would start off slow, where the scent was weaker, and speed up as he closed.
Dogs can be trained to hide and to lay down when they acquire a target, and to make a small yelp into the microphone. This is not hocus pocus. It has been done.
The Rhodesians would use forces inserted by air to box the enemy, and then crush the quarry with speed and efficiency. They might find track that was seven days old, and within two hours track it to where it was an hour old, which was close enough for boxing and hammer and anvil.
The Rhodesians took few casualties, and their tracking and martial skills forced the enemy into reaction mode.
Tracking Taliban in Afghanistan would not be more difficult than tracking Neil Armstrong on the moon.