There's no point. Apart from the Franks, Roxolani and Sarmatians, the hording factions are nowhere near their goals at the start. They simply must horde and move away. The Roxolani will be driven off by the hordes or Sassanids, and Sarmatians are always attacked by hordes and the Romans anyway, so hording is in their best interests. The Franks are the only ones that don't need to horde.