The Stuart tank as a main battle tank

The American Stuart light tank used by the 4th Armoured Brigade in the Crusader Battle was never intended to be used they way they were used in the Western Desert. They still were used in the cavalry role for raiding transport columns, but they were mainly used interchangably with Crusaders as what we call now, main battle tanks. I would guess that the reason that the Stuart survived in that role until July 1942 is that the 37mm gun was pretty potent. That seems to have been mainly due to having APC shot, while the 2pdr shot, at this stage, lacked a cap. The 37mm could penetrate the face-hardened German armour, such was we just saw in Robert Crisp's description of the action against a dozen Pzkw II, III, and IV tanks.