I think it would be funny to try to stick of Sovereign inside a borg sphere.
well it would fit! That sphere was huge i think we can assume that we have different types of spheres. A scout, a tactical long range cruiser (drone) or the endgame one, the escape sphere one...
naw...we've only seen one type of sphere. Remember a sphere doesn't have to much bigger to than the Voyager and still fit insidge a 3040 meter Cube.
I haven't seen enough evidence to suggest 2 different cubes.
Honestly, the last two episodes of VOY gave us to tools for an entirely new Star Trek game. A lone borg sphere weaving its way through a dense asteroid field swallowing little chunks of rocks as it braves its way through remains of a long dead solar system. Behind it are 4 armored Intrepid class starships in hot pursuit. Suddenly, the sphere opens its hatch and takes in a stray omega particle and the armor on the Intrepids disappears allowing the sphere to assimilate as many as it can for 5-10 seconds before the armor returns and the chase is on again. Every once in a while there a hunk of dilithium floating around for the borg to take as bonus points. The tentative names of the game..."Pacman: The Final Frontier", or "Pacman: Assimilation".