Most of the clauses in the Constitution were written the way they were to correct a problem or defect in government we experienced as colonials under the British Monarchy or as independent, sovereign states under the Articles of Confederation.
Today, the corrupting influence of Executive appointments was debated. In the recent past, enormously powerful Royal Governors, appointed by the King, regularly compromised the popular branch of colonial governments, the Assembly. Not only could Governors veto colonial bills, and even dissolve Assemblies, they offered judgeships, government contracts and other forms of patronage to Assembly members. An Assemblyman who owed his concurrent job as a customs agent would be a reliable point of support for the Governors policies.
So, a lesson our Founders took from colonial experience was to rein in Executive power. The State Constitutions of 1776-1777 empowered legislatures over their Judicial and Executive branches. As long as the people dominated, via their reps, liberty was assured, or so they thought. Legislatures made a preponderance of appointments, including judicial ones. In most States, they appointed Governors. The downside was erratic government subject to passions of the day. Paper money, stay and tender laws, and laws which contradicted the Articles of Confederation were problematic.
Faced with recent experience of executives too strong and subsequently too weak, our Framers sought a solution, and in the process gave us distinct separation of powers. Legislators were prohibited from simultaneous service in the Executive branch and were constrained from creating such offices for their enrichment after elective service.
The common error in planning any military strategy is the seeming near impossibility of calculating the people problem.
The same seems true of the Con-Con ? How can I aptly say what others will do when I so often on a whim do opposite what reason says I ought.Governments after all consists of men as fallible as I. Better to let them make their errors then respond that to speculate as to what they will do.