One of the problem the British tanks faced when fighting the Afrika Korps was their out dated and obsolete anti tank guns that were mounted on the Crusaders and were handed out to the army regiments.

The British two pounder gun was short ranged and could not fire explosive rounds which made it useless against German anti-tank screens that included the Pak38 and the 88mm anti tank gun. NIall Barr writes:

... by 1941, British tank crews could only effectively engage German tanks at 500 yards range while the German tank crews in Mk IIIs could engage at ranges up to 1,000 yards.

Indeed the two pounder had never really been suitable as a tank mounted weapon because it was not a dual purpose gun. The small bore gun didn't allow the use of an effective high explosive shell.

British tank designers, having absorbed the importance of mobility and firing on the move, mounted the gun so that it was perfectly adapted for firing on the move, but when the tank stopped to fire, the mount remained less steady than a fixed mount designed to be fired at rest.

As a consequence the British used to charge the German tanks in the hopes of getting close where their little gun could be effective and the German tanks would then retreat behind an anti-tank gun screen which would knock the British tanks out.

The British tanks could not engage the anti-tank screen with high explosive shell and would have to continue to charge in the hope of wiping out the gun crews with machine gun fire.

The German anti-tank guns were too well camouflaged and placed for that. As a consequence the British tank crews took heavy and unnecessary losses as their equipment was not up to challenging the German tanks.

As America entered the war it started supplying the British Eighth Army with tanks. One of those was the Grant tank. This was on the same tank base as the Sherman but more importantly it had a large 75mm gun mounted in a sponson on the side of the hull.

There were flaws with the Grant; it was a tall tank that could not go hull down with the 75 mm gun, and the sponson had a limited range of freedom, however it was a large advance over the Crusader as British tank crews could shell German anti-tank positions with high explosive rounds and could duke it out at long range with the German tanks.

There were some other interesting aspects to the Grant. American industry was starting to churn out these M3 based tanks and consequently there were no spare parts. Just complete tanks. The British had issues repairing tanks because of this.

Another problem was that the American armour piercing shell was not hard enough to pierce German armour. The British ended up using captured German 75mm rounds and capping the American shells with the German rounds to make an effective armour piercing round.