I thoroughly disagree. While it's not freedom per se, more political units puts downward pressure on the existing political units, forcing them to act closer to the desires of those they govern. This can be seen in the flexibility and responsiveness of local governments as compared to state governments, as compared to the federal government. The argument that "well DC would love a secession war because it will level everything" also doesn't jive with what we know about modern insurgency and guerilla warfare. What was true nearly 200 years ago is not necessarily true today, and I would think that a large number of US troops, if asked to fire upon people who were their countrymen just the other day, would either refuse outright or refuse once the reality of marching on domestic soil set in.

As someone who was a US soldier, I can tell you right now that I would have refused to march on a seceding state. That was one line I absolutely refused to cross, and I know for a fact that I'm not the only one.