I think that’s a weak argument as the front of the turret is the thickest armor of the tank.And a bustle rack will be directly exposed to a hit by ATGMs and other shells.
If you penetrate it from the side, that's fine. But if you penetrate the front of the turret and pierce the ammo compartment door as well, you're creating an opening between the ammo compartment and the rest of the vehicle, so some of the energy, heat, and toxic gases from the cook-off will be diverted to the vehicle's internals.
I mean if the enemy has the capacity to penetrate from the front the tank. Said tank is pretty much doomed no matter where they take the hit.
Hits from the side also don’t necessarily mean cook off. People have a bad habit of over simplifying the area in question. Top or rear attack absolutely, yet other tanks we know these are also killers. Older generation of Merkava have been destroyed when RPG or ATGM have hit the rear doors. Most tanks are at best immobile as a result. But the advantage of the bustle is as long as a set of circumstances are not going wrong, the bad day lotto. Chances are the hit to the bustle rack will be isolated to the bustle rack even in the event of a cook off Hell even T90 and T14 store additional ammo in the bustle rack.
Where possible and where safe. But just having a smaller turret doesn’t mean the tank is safer it just means in theory it’s a smaller head on target. Increasingly though we are seeing attacks from the sides, rear and overhead. Hit a unmanned turret from the side it’s the same size as a manned. The rear smaller target yet the bustle still has ammo in it. Hit it from the top it’s just as likely to cook off.AFV design 101 - the turret is always the most vulnerable part of an AFV.
Strive to put all your vitals below the turret ring unless necessary
Diameter or rather caliber in guns often means length of cartridge. 120mm and 140mm are actually the same diameter of shell but the casing is significantly longer and heavier to account for more propellant higher pressure and a longer heavier sub caliber rod. Same for 105mm vs 120mm. The problem for APS vs KE in this case is trying to propel the HE countermeasure to intercept at such a distance from the AFV host so as to ensure enough deflection that it’s no longer effective. To close it doesn’t tip enough farther out the less efficient the countermeasures.
By complexity I am referring to the building of the countermeasures themselves. Trophies countermeasures detonated directionally against RPGs a bit like a Claymore mine. More sophisticated system like Ironfist have an airburst element.
Bradley on the whole has been maxing it’s self out for sometime. Maxed out armor reduced ground clearance and power to weight. Maxed out electrical limiting growth. This is why OMFV is in the lead.