Anne Curry has noted that several retinues who lost men from illness during the siege of Harfleur in 1415 managed to find replacements for some of their losses before they marched away to fight at Agincourt. Where did these men come from?
Curry argues that either extra men crossed with the original force or reinforcements arrived later, but I think there is a better explanation.
We know that dysentery killed some leaders like the earl of Suffolk, and sent the duke of Clarence, the Earl Marshal and the earls of March and Arundel home as invalids.
Suffolk had a son and heir to take command, and the Earl Marshal and earl of March had trustworthy subordinates who preserved their retinues as ongoing units.
What happened to the Clarence and Arundel retinues after their leaders went home as invalids is unclear.
But it seems very plausible that some retinues lost enough of their upper command that they could no longer continue as independent contractors. This was particularly likely when the retinue was small, and some consisted of only a man at arms and three archers. The remaining fighting men would have sought and found employment in continuing units with vacancies.