The long awaited sequel is here! We're not just saying "no" to shieldbots, we are COUNTERING them!
Shieldbots' greatest strength is when they gather in a huge ball. Alone, they lack the synergy they need to be intimidating. They also lack artillery units to attack the enemy's artillery with, besides expensive racketeers that make the army less effective at destroying your stuff.
Therefore, when you see a shieldbot factory early in the game, harass it. Don't let it build up to power, and by lord, don't let the shieldbot player get decent artillery from other factories. Strike when they are vulnerable, mow the enemy down with weapons they can't attack, and reach a safe victory.
Good luck, anti-shieldbot soldier. We're proud.
<Note: The anti-shieldbot organization does not encourage bullying outside of battles. Let even the worst of rivals share a drink in time of peace.>