Here's a sort of strange example: Metal Saga on the PlayStation 2 (no relation to the SaGa series).
In this game, much of the time you will be fighting in vehicles (though it's possible, and sometimes necessary, to fight on foot). While in a vehicle, when you take damage, your vehicle will lose armor until it reaches 0. (You can buy more armor in a garage, but that's the only way to restore it.) If your vehicle has no armor, the hit will damage a random part of the vehicle, and if the same part gets damaged twice, that part will be disabled. This can result in getting fewer attacks, or it can even make the vehicle unusable, forcing its driver out to fight on foot.
Now, it turns out that, later in the game, it's actually easiest to go without armor on the vehicles, as armor slows the vehicle down. By eschewing armor and choosing to use only weak but lightweight weapons, you get more turns, and if you are at a high enough level to compensate for the weapon's lower power (the formula seems to be additive), you will do damage faster. If your vehicle does take damage, you can repair it in the field, whereas you can't replace armor in the field.