Just a warning this is going to be a long piece, but, I hope you guys enjoy them.
So here's a chart to show the evolution of the light tank in Daemyrtian service. Starting at the top, introduced in 1921, is the LT21. The LT21 is a locally produced variant of the FT17, mounting a .30 caliber machine gun in a one-man turret. In 1926, the model was up-gunned to the LT21-37, mounting a 37mm gun in a slightly modified turret. These were then followed by the first indigenous design, the LT29. The LT29, introduced in 1929, was a longer vehicle, with better suspension and a more powerful engine. The First two year's production models were equipped with the older LT21-37 turrets due to unforeseen setbacks with the new cast turrets meant for the model. These were remedied on the LT29/31 model, which mounted the turret meant to equip all vehicles of the type two years earlier. Following the trial of the cast metal turret on the LT29, the Armaments Procurement Board decided to place a requirement for a vehicle with both a cast hull and turret. The winner of this competition was the LT34. The LT34 was a smaller vehicle, mounting a specially-designed light 37mm gun, and carrying a more efficient engine than its predecessor. This, coupled with the superior suspension, led to a much better tank to fill the reconnaissance and cavalry roles that the previous models had been used for. Three years later, in 1937, it was decided to create a variant specifically for reconnaissance. This was the LT34-20, mounting a 20mm cannon and boasting a larger engine and strengthened transmission. The pinnacle of Daemyrtian light tank technology, the M43, debuted six years later. The M43 moved away from the older one-manned turrets, and increased the size of the vehicle's crew to three. Mounting a 45mm gun, it was exported to the Russo-Spanish Empire as part of an modernization program. In 1952, the design was slightly revised into the M43B, which was equipped with a better radio, engine, and a redesigned, lower profile, commander's cupola. Finally, 21 years after the first M43 rolled off of the line, the M43C was introduced. These featured a completely new engine and transmission, along with a larger bustle and a 40mm autocannon. These vehicles were used in both the reconnaissance role, and as a light tank to support marine landing units. This model served for about fifteen years, before being phased out in favor of faster, more maneuverable wheeled platforms.