As a shield specialist, I am always happy to see rovers against me.
Rovers have a hard time against shields, that's just how it is, and you will be fighting uphill. The mighty Fencer is worthless against shields, and so are things like Impaler and Badger.
However, useful advice was given.
1) Shields are slow. You are going to have to exploit that and raid HARD. I hate it as a shield player when an enemy shifts the axis of attack and I have to plod my shieldball across the map to deal with another threat.
2) Porc is your friend. Let me explain. The #1 reason why shields are bad boys is Felon. That mob enforcer can dish out huge amounts of pain at a long range. BUT, Felon runs flat pretty fast. So you have to drain the shield charge somehow, and Razor is a great way to soak up Felon charge.
3) Scorcher and Ravager can be strong if you time it right. You have to wait until the shieldball is pink-red. At that point the batteries are running close to empty and its the right time to counter attack. A bunch of Scorchers overrunning an energy flat shieldball is my nightmare.
4) Use Cloaking devices. A good shield player will retreat from charging Ravagers and keep them exposed to the wrath of the Felons for as long as possible. The moment I see a Ravager blob I typically engage from maximum range with Rogue, and retreat the moment the Ravagers charge. Now, if I'm advancing without a care because I see no Ravager blob, because its cloaked, then the Rover player has a good chance of running the Ravagers into the shieldball and doing some real damage.
5) Use Dominatrix. Dominatrix is a pain in the ass for a shield player because it ignores shields. Domis can typically pick off the shields on the edge of a ball and retreat before getting zapped. Do this a few times and the ball will get degraded.
Cloaking tactics against a good player will only work once, if that, though. The moment I see cloak fields I spam dirtbags as a forward guard, and so will any decent player, so time the trick well.