Yes, seriously.
Shermans weren't even on mass production yet.
Heaviest british armor was sub par crusader, which was pretty much upgunned stuart with slightly better armor, which was still paper thin.
The Matilda II became notorious for it's impervious 78mm frontal armour which at the time was very impressive and difficult to handle. Crusader and Valentine tanks had their issues but it's not as if the Germans possessed any vastly superior tanks. Most of Rommel's armour consisted of Panzer IIs and IIIs, later on a few Panzer IV F2s and some Tigers saw action as well but their numbers were too limited for them to have decisive impact on the outcome of the theatre.
Having StuG IVs and Fireflys in Africa would be about as absurd as a King Tiger in 1940 Belgium...wrong time and in this case wrong place to boot.