"This is how we do it in Italia!" - Some Arditi, probably

Explanation: In the later stages of WW1, Imperial Germany sent elite assault troops, ‘Sturmtruppen’, to assist their… beleaguered ally Austria-Hungary against Italy. These German assault troops had their teeth cut on the trenches of the Western Front, and were some of the best that Germany had to offer. Specialized assault troops of this kind were a new innovation in WW1, and Germany was one of the quickest to adopt this new form of warfare. For that matter, Italy had been slow and reluctant to adopt assault troops, who Italy referred to as ‘Arditi’, at least officially. Surely, German stormtroopers would be a massive boon to Austria-Hungary!

While assault troops, as their name implies, are generally not used in defensive situations, the confused back-and-forth combat of WW1 meant that the German and Italian assault troops would get mixed-up and clash in the coming days - especially as German assault troops were often used in swift counter-attacks. And the Arditi regularly emerged the victors.

Much of this was due to the different combat environments they had trained for rather than any ‘direct’ inferiority of the German assault troops - the trenches of the Western Front on WW1, and the immense concentrations of artillery, demanded different skillsets than the confined, mountainous terrain of the Alpine Front. And the the Sturmtruppen were on the Arditi’s home turf!

German Sturmtruppen practiced tightly-coordinated and timed assaults by night or with artillery cover, employing covering fire to maximize speed of approach when discovered by enemy positions, and widely using pistols and submachineguns in addition to grenades and melee combat to clear tightly-occupied trenches with maximum speed.

Italian Arditi, on the other hand, were noted as brutal practitioners of ambushes with hand-to-hand combat, and would sometimes make assaults with only grenades and knives (it ‘encourages’ aggression when your only option to fight back is to get closer).