All tanks have front, side and rear damage resist values, thats why shots in the rear of the tank do a lot more damage. On all tanks the front takes less damage even without any armor attachments. That's the armor bonus we're talking about adjusting, not the attachment. That will make Magriders a lot more "Fragile" so all they would have to keep themselves safe is the ability to avoid damage. There are still concerns to work through with this possible change as it obviously affects a lot more than the tank vs tank balance for the Mag.
Just to reiterate, none of this is set in stone, I'm just letting you guys know what the vehicle balance team is considering and experimenting with right now to try to bring the three tanks a bit more in balance. There may be more changes, there may be completely different changes, we're still keeping all options open.