The so-called Emperor does not skimp on feeding his troops.
In Pei Xuanjing's plan, if he wanted to tell this story in this world and direct this play, having Wood Virtue Star Lord play the leading male role, it was only natural to compensate him; otherwise, it would be somewhat unreasonable.
Although, given Pei Xuanjing's status, he could have demanded participation solely based on the interests of the Great Ming World and the righteousness of the Heavenly Court without promising anything in return, he chose not to do so.
The story of Zigong Redeeming the Cow already made it clear that while Pei Xuanjing could use morality to bind Wood Virtue Star Lord, there was absolutely no need to do so.
They were not incapable of affording the compensation. The benefits of integrating this world into the Great Ming World were immense, enough to benefit all the strong in the Great Ming World. Why make one's own people suffer unnecessarily?