Centurion shield overpowered
Literally any attack destroys the Centurion's shield. Send a rifleman in to kill the shield before the Titan fires. Then it has a several second countdown before the shield comes back.
Whatever the first attack is will do no damage at all to the Centurion. Once the shield is down, you start dealing damage. Use your slow-firing, heavy-damage weapons after the shield is down.
Also, the Centurion is a heavy anti-vehicle vehicle. If your Titan's first shot is what takes down the shield, the Centurion has a nasty tendency to win the matchup. In your case, we hope the MG squad is the first to engage and kills the shield. The Wolverine is a decent shield breaker, but is really here just to be cannon fodder and should run away if you don't need it for anti-air business. If at all possible, the Titan should completely avoid the Centurion and its large cannon until the MG Squad has killed the shield, then it should run in and blast it.
As for your Ion Cannon, it sounds like it hit right as the Centurion's shield came up, and thus acted as a shield breaker again, causing no damage. Ouch. I feel your pain. I have done that before.
