I'd concur. Withdrawing the general's unit before the enemy could get it, especially as it was a high Valour governor, would be very wise. Especially as withdrawal doesn't earn him cowardice vices - isn't discretion a better part of valour?
Peasants would fare poorly against anything to start with, and against the Spanish Jinetes they would melt like snowball in hell after second volley of javelins. On the other hand, panicked flight with infantry is unwise when the enemy does have a cavalry unit ready to ride your men down... at least unless you have something else to make the sacrificial last stand.