[Taqwus]

Um, no.

First of all, RoTK was not, is not, and likely never will be an accurate warfare simulator. It's model of "on-the-battlefield" bribery is truly outrageous.

Second, bribing commanders and troops just wasn't that historically common, outside of the Afghan civil war. Even there, it was mostly in strictly temporary deal-making between leaders who considered themselves sovereigns, not subordinates facing execution -- possibly by their own troops -- for treason. In wars between nations, it'd be just about unheard of IIRC.

Third, off-hand I can think of more assassins and would-be assassins that struck due to existing military conflict, differing ideology, or belief that their government otherwise was leading them down the wrong path than due to bribery.