the glass shards were not hurled at the ground, they were dropped. so they will fall at a normal speed until they hit the ground because of their randomly shaped shards have a bit of drag because of the air. in theory, because of gravity and their armor you might as well be throwing smooth rocks at the armor. now, let's not mistake a diamond for a strong material. sure, it's hard, but very, very brittle. you can scratch a symbol into a hammer with a diamond, but you can also shatter a diamond with a hammer. When RG-03Charlie dove on the diamond reinforced glass spike, not only was the diamond hit by the thick metal of the shield but also the sudden force and weight of RG-03Charlie's body, causing either the diamond glass spike to bend out of the ground sideways or just shatter everywhere.
a bit of a science lesson there, but still.
RG units 05-14 have arrived and are setting up a mounted LMG.
Tuba Knight charges at you.
"Those who threaten the safety of His Majesty must perish! To victory or death, let this be our greatest symphony!"