L5
The L5 was a renowned light tank at the time of its introduction due to its blistering speed and firepower. In 1342, the 40mm was more than capable of defeating any armor it faced. The L5 was a favoured vehicle against the Arcadians, but as the World War dragged on into its 2nd and 3rd year, its deficiencies had become apparent. The 40mm gun, while excellent at the start of the war, was a poor anti-infantry weapon and could not defeat mid-war medium tanks fielded by the Siegs.
Despite this drawback, the L5 had been built in such massive numbers that it was used and modified throughout the war. To make it a better infantry support vehicle, 'P' variants of the L5 were created - of which armed the tank with 75mm and 105mm howitzers, whose HE warheads were better suited towards hitting groups of soft targets.
The marines in particular preferred the smaller size of the L5 in the Scyllic theater, were the thick jungle made it somewhat difficult for larger tanks to advance.