It's not silly. The so-called CSA was not able to maintain its territorial integrity for a single day. You can declare -your- independence and do better than that.
Secondly, despite the conventional wisdom, the rebel effort was very lame. It had almost no significant success outside northern Virginia. Think about it: With the exception of Chickamauga, rebel arms had almost no success except right around Richmond. Grant's advance into central Tennessee early in 1862 was never seriously checked until Shermaan brought it home at Savannah, Charleston and Columbia.
Rebel arms --including the Army of Northern Virginia --had as little success outside rebel territory as some Union commanders had in it. Put another way, Lee had as much success outside Virginia as Pope, Hooker and Burnside had within it.
The "insurgent area" was 10% larger than the loyal area. The loyal states had a 3:2 ratio in manpower. Military threory holds that it takes 3 attackers to dislodge one defender. On paper, the rebels couldn't lose. But they snatched defeat from the jaws of victory.
Walt