Not sure about the 2pdrs , I didn't think standard infantry battalions had AT gun platoons until 1943, when the original HQ Company was split into HQ Coy and separate Support Coy.
But Vickers MMGs were NEVER part of the infantry battalion line up, they were organized into Machine Gun battalions.
Having said all that, the battalions at Dieppe might have been re-organized, I don't know.