I don’t believe your suggestion about the purpose of the second amendment here is accurate.
The founding fathers were less concerned about entrenching their own power, than they were about preventing the overreach of government power and recreating the tyranny that they had just fought to overturn. Support for the notion of an insurrection in the face of tyranny was absolutely a thing that these men had demonstrated immediately prior. They were, in a very literal sense, insurrectionists, and there was reason to think that tyranny could return given that’s how it worked everywhere else in the world.
And in their own insurrection, the fact that the colonists widely held firearms that were on par with those of the military they were engaging certainly played a key role in the success of the revolution.
Now, in no gun fetishist, and I believe that in the current military environment the difference in power level of the actual military and since folks with small arms makes such an armed revolution virtually impossible, so I’m not sure it makes sense, but I still don’t believe that your suggestion surrounding the motivations of the second amendment is accurate.
To be clear, even if you embrace the understanding of the 2nd amendment which focuses on the initial clause taking about a militia, the second amendment is STILL somewhat about an insurrection. It merely places that capability in the hands of the States, guaranteeing that they can form state militias in order to, potentially, secure their own rights from the federal government.
From Cornell Law’s page on this subject:
The Second Amendment is naturally divided into two parts: its prefatory clause (“A well regulated Militia, being necessary to the security of a free State”) and its operative clause (“the right of the people to keep and bear Arms shall not be infringed”). To perhaps oversimplify the opposing arguments, the “states’ rights” thesis emphasized the importance of the prefatory clause, arguing that the purpose of the clause was to protect the states in their authority to maintain formal, organized militia units. The “individual rights” thesis emphasized the operative clause, so that individuals would be protected in the ownership, possession, and transportation of firearms.1 Whatever the Amendment meant, it was seen as a bar only to federal action, not state2 or private3 restraints.
The two primary interpretations of this amendment both involve the protection of rights against the federal government… the legal dispute is just about whether it’s protecting the States’ ability to rebel, or individuals.