From Hackmore, Donald Weapons of War: Modern Infantry Small Arms, Victoriana: Hector Military Books, 2270.
Despite all of the advancements in modern battlefield technology, none have replaced the simple infantryman as the most important and indispensable unit of planet-based combat. To the contrary, with the development of devastating weaponry that can be transported by a single man, such as the coil gun (the best known of these being the "long rifles" crafted in Hochstadt, of our own Kingdom of Yellowstone), the famed armoured fighting vehicles of Emperor Henry's days are in danger of extinction. It is well known that a footman of the Rederval, armed with a Hochstadt Longrifle, and aided by orbital relays and spotters can destroy even the most heavily armoured vehicle from as far away as 100km (if the shooter is positioned on a mountain or skyscraper; 5 km if standing at sea level, of course).
Add to this phase weaponry and the infanteer might be said to reign supreme on modern battlefields as never before. He is especially useful in limited conflicts that are on occasion allowed by the Emperor among certain subjects to settle disputes, or in dealing with small as-yet untamed pockets on our own Holy Earth. For the infantryman can be much more precise than orbital or A.F.V. bombardments, minimising harm to local civilians or the world population at large. In the lamentable, but inevitable conflicts between Christians, the Holy See has forbidden the use of modern weaponry and matters are thus settled by the sword and, once again, the armoured fighting vehicle has no place.
In the Martian Crusade, very few such vehicles were transported over the vast distances seperating Earth and the land of the god of war. Given the vast amounts of fuel and energy required to transport anything, it was deemed that a battalion of heavily armed infantrymen would be a better use of limited resources than a massive battle tank. This philosophy ulimately proved sound. In the crucial battle of that glorious armed pilgrimage, the Battle of the Hellas Impact Basin, the Catholic forces were comprised entirely of infantry, many of whom were orbitally inserted using grav-chutes.