Did the generals not know faces of Cao Cao, Liu Bei and Sun Quan?

In the battle of Hefei, when Zhang Liao and Li Dian ambushed and countereattacked Sun Quan to the point he was trapped cause the bridge was destroyed, which nearly made him caught by Wei soldiers. However, Zhang Liao and Li Dian didn't know what Sun Quan looked like, so they focused on attacking Ling Tong. And only when they asked a captured Wu soldier about a "red beard marksman who was good with arrows," did they find out it was Sun Quan, and they lamented about not capturing him. I know back then information was not easily sent, and there was no camera either, but shouldn't there be a portrait of Liu Bei or Sun Quan to show at least the generals, so that they can easily capture those high-value targets?