They store the ammo in the crew compartment, so only if the ammo penetrates into crew compartment can it result in a member kill, similar to M1 where the ammo is sealed somewhere else - any penetration into crew compartment is fatal and survivability is the same. I guess they can also make ammos that won't "cook" when hit.
Dude seriously, Abrams have suffered penetrating hits to the crew compartment and only suffered injuries. it dpends on how much energy the penetration has and what type of penetration. However if the Abrams had combustables in with the crew like the T series do then even minor penetrating hits stand a very good chance of cooking off the ammo so the chances are not the same, not even close.
T-series any penetration stands a good chance of causing a catastrophic explosion
isolated bustle rack storage system, any penetration to the crew compartment must have enough energy left over after defeating the armor to actually deal with the crew.
The Leclerc, Type 90, and SK2, T80UM2 all use a cassette style bustle rack autloader that is sealed away from the crew. The only drawbacks being very ready ammo (about 22 rounds) which could cause the tank to have to stop in combat and manually transfer the remainign ammo from the armored hull storage bins