From the website:
The light squadrons of the armoured regiments embody the dash and daring of the British cavalry. Fast and manoeuvrable but not as heavily armoured as the enemy panzers, they use speed and cover to protect themselves. They are often relegated to scouting or protecting the flanks of the regiment while their heavy cousins, the Grants, take the fight to the enemy.
The Crusader entered service in November 1941, in time for Operation Crusader, the offensive in late 1941 that was named after the new tank. Although the Crusader is vulnerable to enemy fire and prone to certain mechanical difficulties, its speed and cross-country manoeuvrability are admired both by its own crews and their German and Italian foes.
When the up-gunned Crusader III entered service just prior to the Second Battle of El Alamein, it was eagerly welcomed by the crews. The new tanks are shared out among the squadrons, giving each troop much-needed extra firepower.