Here's why:
* Implore and plead both suggest a strong and urgent request, but implore is more intense and desperate.
* Precise and exact both mean very accurate and detailed, but precise implies a higher level of accuracy and detail.
So, the analogy works because both pairs describe a similar concept with varying degrees of intensity. Just as "implore" is a more intense form of "plead", "exact" is a more intense form of "precise".