There is another guy Weber who wrote a similar story(He wrote the Honor series) about some English knights plucked off a sinking ship from the 8th century who were used for the same purpose. Overtime, the adaptability of the English knights allowed them to turn the tables on their captors and take over the ship and start a rebellion of sorts against the ruling galactic consortium.
There’s another one [by I believe Weber also] about Romans captured at Carrhae sold to aliens from outer space who use them as mercs for low tech wars, revive them from all but the most serious wounds, and keep them alive until the present when the romans escape back to Earth. And it gets interesting from there.