Historically speaking uses of cavalry as the “Decisive” factor on the battlefield is relatively modern. Ancient armies consisted primarily of foot soldiers. Chariots did make an appearance quite early but charioteers were really mobile foot soldiers. Early Greek, as well as Macedonian military machine, consisted of foot soldiers (Alexander’s ‘Phalanx’). Roman legion was also an infantry force with cavalry used as ‘auxiliary’.
Asiatic nomads from the Steppes were, however, horse people and fast-moving Hun horse archers of Attila were kings of the battlefield until defeated by mainly the heavy infantry commanded Flavius Aetius at the Battle of Chalons in 451 AD.
It was not until the arrival of the lightly armed but highly mobile mounted Mongol hordes that cavalry ruled the battlefield in the East. In Western Europe however, despite the heroic stories of the Knight (Horse soldier), soldiers fighting on foot were the deciding factor as late as the battle of Agincourt (1415 AD). Historian William Dalrymple in his recent book “ The Anarchy “ describes that 7,000 Sepoys with a few hundred Britishers commanded by Hector Monroe mowed down 40,000 Indian troops including 5,000 veteran Afghan cavalrymen commanded by Shah Alam II, Mir Qasim & Shujjad-doula at Buxar (1764) by ‘volley-fire’ of the infantry achieving a most decisive victory.
Tank based cavalry only came to prominence with the ‘Blitzkrieg’, a German innovative tactic employed ever so successfully during WW2. Germany eventually lost because the Russians and the Western European Allies had also mastered the use of the tank in battle and could exploit their numerical superiority to maximum advantage.
I would, therefore, say that even though cavalry was an important element of the war machine, it was the Infantry that had been the Queen of the battlefield until WW1.
Now my second point. Since the most effective use of the tank on the battlefield is as a 'battering ram' to punch a hole into the enemy’s defense lines and the out-flanking maneuvers using the mobility of the tank force; an ideal tank should have the optimum combination of speed & firepower.
In my view, most modern tanks weighing more than 60 tons are far too heavy thus cumbersome. A lighter tank, (about 28 to 32 tons) but with high acceleration & high speed (say about 50 mph) armed with a heavy puncher but of medium caliber (105 mm) gun is the way forward. There have been sufficient advances in the materials science that ample armor protection is now achievable within the 30-ton weight limit.
Would appreciate comments from military professionals