"Young Lord, stay close to me," Gareth said quietly as he took on a fighting stance. He looked back at Caius and gave him a reassuring smile,
"The Estate was alerted the moment the Carriage crashed. Reinforcements will be here soon. Until they arrive, I assure you, I will protect you."
Caius looked into that smile and the confidence in Gareth's smile and he still didn't believe him. There was just too much of a disadvantage to be overcome here. He didn't have any real feats for them in the original story to refer to.
In [To Kill A Demon Lord…], Caius had never actually been in danger while under the Guards' protections throughout his time at school. His moments of danger and real-life and death battles came after graduation when he was making his own way.