Well that depend on whether you believe a SSD can pack more of a punch than the Spear, IMO the spear does better. Even though the SSD has way more batteries, they can't all be brought to bear at once. Whereas the spears batteries are fuelled by the force, and fire precise, combined, singular shots that can tear capital ships apart. With a little help the Spear would make short for of the Golans.
But yes, you do make a fair point. It is a complex process, but I do believe the SE has the power to disable the planetary sheilds. And there probably is an on/off switch (or something similar), after all Shae Vizla managed to disable the entire defense grid. After all nothings blaster-proof.