"Run! We can't hold on!"
"We are too few! Disperse! Disperse!"
"The enemy is too fast! We can't take such heavy hits!"
"Move away! Move away! Don't let those huge spears hit you!"
Having seen how their mounted riders were dealt with such rapidness, the rest of the infantry could hardly be blamed when they chose to abandon their position en mass to save themselves.
The fact of the matter was Remus really had struck out of nowhere, catching these elite riders totally off guard.
Disorderly and caught out of formation, even if they stayed and did not run, it was highly unlikely they would have been able to stop Remus.
Especially since these men were not even proper infantry, but really dismounted cavalry with much lighter armor and smaller shields.
Not the ideal gear to face a group of heavily clad horsemen.