Understood wouldnt it better if the At4 actually gets reused?
Where you reload and load another missile on it like the carl gustaf and the rpg.
It depends on the tactical situations that are foreseen in likeliest conflict for that sector's unit.
Carl gustav has much larger logistical train because of its multiple fire capability (both no. of shots and also diversity of munitions).
So it gets a bit more complicated to say have a guy dedicated to carl gustav in a platoon, and have him well trained on it and then what are the complexities involved in his decision making (in real time conflict that happens) in either provisioning with him (or having him select the most appropriate one for whats in front of him) with say round C among round types A - Z etc....and then maybe change that for next encounter and so on.
Whereas AT4 is single shot, and lot of engagements are more ideally met for it and you just provide a standard round for it across that sector etc. ...and you dont have a train up a guy extensively in its dedicated use (pretty much any grunt can be trained on it basically quickly etc and you just issue as much as you want to the unit in more quicker decision format).
I believe it (AT4) turns out overall better than Carl Gustav when you expect many more stationary hard targets in front of you etc given this....whereas Carl Gustav is great if you foresee more diverse kind of targets (stationary, mobile and whatever armour levels involved) since then its round diversity and re-firing use are brought to bear more effectively.
So some mix of both is probably ideal for large military depending on what it wargames and trains on regarding sectors it has versus opponents.