Wouldn't be as much of a 'bombardment of death.' You'd have to be in range of both surface-to-orbit weapons and the defense satellites in order to take down the defense satellites and a dronefleet in the planet's orbit- and yet doing so will mean heavy damage to you. Stying well away and launching masses of projectiles from railguns will make you use up ammunition, energy, and supplies, while both defense satellites, the fleet, and the planet's surface defenses will be able to pick off all the dangerous shots. After all, they can just pick off the ones that would hit something important, and leave the vast majority alone. Not only that, but what's to stop the Draconians from making a shield? A planet could have generators that would produce far more energy than a fleet could. They could keep it up to block projectiles raining down on important targets, and let the rest hit the ground- no harm would be done. Defense satellites and ships would have plenty of time to move out of the way of enemy rounds, as well. And if they were firing so fast that they couldn't be avoided, then you'd be doing what's essentially nuclear-warheads in every bullet from a rifle. Too high velocity would be making it extremely powerful, OP-level powerful. Lasers and other weapons like that can only go so far before the energy sputters out- energy weapons can't be used quite as distantly flexible as kinetic weapons.

Rebuttals, anyone?