What are some of the differences between accountants and auditors in the compliance context?

In the compliance context, what is a “gatekeeper”? Your reading this week describes “two concepts” of gatekeepers—zealous advocate or public servant. What is meant by these competing concepts? Which do you is optimal?
What three notable special advantages do attorneys bring as gatekeepers? Explain each of those advantages in the compliance context.
What is the “up-the-ladder” provision in ABA (American Bar Association) Model Rule 1.13? What are the competing interests and policies at stake in the rule? Does the rule adequately effectuate and balance those interests?
What are some of the differences between accountants and auditors in the compliance context?
How has the Sarbanes-Oxley Act changed the auditing and related compliance landscape?
Relatedly, what is Sarbanes-Oxley § 404(b)? How does § 404(b) complement the overall compliance landscape?