Take Dong Zhuo or Lu Bu or Sun Jian and his Jade Seal as an example. It seems for me at least that some factions character combos almost never seem to redeploy after being defeated making it impossible to acquire either those characters or their unique items.
The situation varies from who you play and how the game evolves, one example would be I played as Gong Du and defeated Lu Bu early game and only after like 100 ish turns after I destroyed his faction would he show up again in another faction.
Or if you play early and fight Liu Biao and defeat him but not get his bow.
Anyone else has trouble with such situations?