[kornork]

Honest question: who else, internal to the executive branch, and besides the president, should be able to interpret the laws for the executive branch?

By my reading, this is a clarification that if an agency makes a significant policy change or regulation, they ought to run it by the president first.

It doesn't preclude other branches of government from checking this power.

[acdha]

Agencies all have their own lawyers, and it’s frequently useful to have them hash out agreements for the same reason that it’s useful for scientists to get peer review. Beyond the basic efficiency argument, it’s good to have multiple people validate your reasoning.