Ok, I will venture a guess. Mass infantry attacks on horseback with kevalar body armor for the horsemen and the horses. All ceramic and plastic weapons and no electronics.
Tatics such as dispatch a calvary unit to a given target by dispersal and regroup on point for the attack, a form of blitzkrieg to the Nth power. Little if any defined lines, civilian slaughter valued for its shock value.
Horsemen without any metallic objects dispersed over a wide area are virtualy impossible to stop with present weapons. You cannot see them well with any modern sensors, anti tank weapons will become smaller and lighter giving the firepower of a tank to an infantry man.
With good electronics you can pinpoint a wrist watch's location from a couple of miles due to its electronic emissions, so nobody can carry detectable junk or they will be auto targeted.
The way past smart bombs is to become-un targetable. The way to do that is to become non emmisive and non detectable. Kevalar not only stops balistic fragments, But also reduces heat emissions.
Horses do not need fuel, they eat bushes, and a herd of horses look like a herd of deer to infra-red sensors.
Yep, things will change, always has, always will.
That is about as strange as I can push it, any other wild ideas out there?
Horse mounted infantry almost never fought mounted.
They show up just fine on thermal sights.
they have a different breed of bacteria in their intestines, which allows them to digest browse, like a deer, instead of needing good quality grass. Simply put, they can live and prosper where a larger horse would starve.
In order to be able to live on forage, the animal has to be raised from weaning to adulthood on rough forage.
ping
So? In a battle, they'd both get shot down easily enough.