Longaxes makes 24 shield damage, and I love this weapon because it breaks standard wooden shields (24 HP) whith only one blow.
Ancient auxiliaries shields have 16 HP and but I need to blows to break them. With only one blow, after finish combat, I see they remain at 18% of total HP, as if they had an initial HP value of 32.
Furthermore, I lost an incredible level3 battle in the previous campaign (and previous version of 1.1) against legionaries because I needed 2 blows to break each shield and my 2 longaxe soldiers soon became exhausted.