This story is a sequel to Prince Blueblood: The Politician
Prequel simply establishes Blueblood as a politician, no story elements present at all.
Princess Twilight Sparkle appears to have some trouble with politics, as her encounter with the yaks proved. On her second go-around, Prince Blueblood accompanies her for some valuable pointers. The buffalo incident and the yak incident were both resolved by Twilight's friends, not Twilight alone, and as a Princess, she needs a bit of help.