Mighty_Zuk is correct on each point, but IMO the Russians made the right decision in going with the fixed launchers.
A swiveling launcher's response time disadvantage grows more pronounced as the interceptor mass increases, and both reaction time and interceptor mass (and thus payload) have an effect on the system's ability to degrade incoming long-rods.
The further away from the vehicle the interceptor intercepts the long-rod, the more the long-rod will yaw before it strikes the vehicle. The larger the interceptor warhead mass, the more explosive power and fragment mass it will have (or the larger its linear shaped charge width, if they're going with the Nozh approach).
Russian tanks are relatively light, and even though they incorporate ingeniously mass-efficient armor, they lack the mass budget to stop western long-rods. In ODS we saw how very overmatched Saddam's tanks were against the older generation long-rods. Armata has an innovative redesigned armor envelope, but its mass budget is still quite small. Afganit APS needs to degrade long-rod threats sufficiently to prevent them from punching through their armor.
A swiveling launcher like Trophy might be able to get interceptors on-target more precisely and reliably, and it might be able to make use of more of its munitions in an engagement, but this means nothing if an interception does not prevent the vehicle's armor from being defeated.
This is speculative, since pertinent details of Afganit are not known, but I suspect Afganit's fixed launchers means much larger, heavier interceptors can intercept long-rods far enough distant from the vehicle to prevent the long-rod from defeating the vehicle's armor.
Of particular interest is whether Afghit's interceptors have straightforward fragmenting explosive warheads, or if they incorporate a side-facing linear shaped charge (similar to Nozh's linear shaped charges) for cutting a notch in the long-rod's side. That would change the character of the protection afforded, and also make Afganit's effectiveness less sensitive to the distance between the vehicle and the point of interception.
Edited because I misspelled Armata, but also to add: Trophy's approach still makes sense for the IDF because of the differences in the problem they are trying to solve. Merkava (and western tanks in general) has comparatively heavy armor, and the long-rods thrown at them are comparatively less effective, so a successful intercept does prevent penetration. The Russians are facing a different balance -- lighter armor, more effective long-rods.
The approach of tilting a rod does not require a lot of base armor. Even the side armor of at least most tanks would be able to resist the residual penetration.
IMI, in their marketing footage, showed a the effects of a tilted rod against steel plates, in two extreme cases (target plates were placed in similar value positive slope and negative slope). In one of the extreme cases, only paint was removed and maybe 2mm were 'slapped off'.
In the other, the teething effect tore only a few cm into the steel plate.
The defeat mechanism would not involve any fragmentation. It's why IMI says their warhead is fragmentation-free.
Afghanit's warhead may intentionally contain a small section of fragments to defeat ATGMs coming in at odd AoA, such as diving, or from between the axes of the launchers.
Anyway, the main defeat mechanism would be a strong, fragment-free blast creating a tight ring of force that would push the rod.
Position is extremely important because the closer the blast is to the tip or tail, the better the yaw.
If it's close to the center, it may just push it downwards and still degrade penetration, but not complete defeat.
Fragments would simply fulfill no function.
@ ~ 3.00 here: