Complex sentence: Larger Matilda II tanks were amongst the Matilda Is, which advanced through the artillery and anti-tank fire unscathed, German shells bouncing off and the tanks destroying the German anti-tank guns, with return fire and by rolling over them, killing the crews.
Split into simpler sentences: Larger Matilda II tanks were amongst the Matilda Is, which advanced through the artillery and anti-tank fire unscathed. The German shells bounced off with the tanks destroying the German anti-tank guns with return fire and by rolling over them, killing the crews.