As for whether doing this will seriously weaken the Sulun Family's power, the Kalan Family does not care at all. The two sides have fought for hundreds of years, and they are well aware of each other's strategies. Even if they add some royalty, at most, the Sulun Family will suffer a little, probably not enough to cause serious damage. After all, if you can't win, you bow your head, everyone understands, because there's still some favor left.
Thus, the Kalan Family willingly accompanied Vologases V, however, the Kalan Family did not know that Vologases V's initial purpose was to decisively harm the Sulun Family, at least to strip them of the right to crown the king.
Of course, this purpose, even if Vologases V had told the Kalan Family, they would not have believed it. However, sometimes reality is more magical than fiction. After all, reality can operate without logic, whereas novels must narrate some truths.
