Tbh the main problem for me is how inconsistent their effect is accross vehicles, e.g. for some they’re an extreme disadvantage, e.g. significantly reducing survivability.
Best examples would be the Leopard 2/M1 with their baskets, as not only does it prevent the turret from rotating, they also create a ton of spall, usually more than the plate penetrated prior, which essentially guarantees killing the entire turret crew outright.
On the other side, there are the autoloader modules, which don’t create spall but solely absorb it., which especially for soviet/russian mbts is a massive survivability buff that goes right against why gaijin proposed the addition of these modules in the first place; Not dealing damage even when properly aiming.
And I think we can all agree that shooting a T-Series tank directly under the turret side-on (i.e. where all the ammo, charges and 2/3 crew are located) should do a bit more than disabling their ability to reload… (Especially because it doesnt remove the shell in the breech like on almost every other tank with a autoloader module.)
The FCS on light tanks is also implemented with pretty much 0 effort or regard to backup/Independent systems. For example, R400,using a TH 301 turret with an addon AOZ 2000 TVD should have 3 Independent FCS parts; The TZF-LA main sight, the TVD (it has a separate display-device and ballistics/fcs computer) and the commander-sight, which also has an additional ballistics computer and is Independently stabilized.
On some tanks, the FCS disables stuff the FCS is actually intended for, i.e. thermals/nvd, laser-rangefinder, stabilization, irst, etc. yet on others, even such that that do not rely on monitors but have periscopic sights, the fcs disables literally everything except driving.
This would be fine for vehicles with crewless turrets or fully decoupled sights (i.e. use of the sight solely through monitors) , but makes absolutely 0 sense for periscopic sights.
The FCS/other modules are also often modelled with 0 regard to historical accuracy and essentially made up entirely, perfect examples are: Begleitpanzer 57 mm (everything was made up) or R400 (the TZF-LA related block looks okay’ish but everything else is a literal insult).