I haven't read about Nagarjuna's claims nor I have read or heard anywhere about such claims, but I know Nagarjuna is speaking the truth.
What is the truth?
An effect always arises independently of the cause.
A cause always arises independently of the effect which produced the cause.
All causes and effects arise completely independently.
There are no causes, nor effects.
Everything arises and ceases independently.
Thus, everything being independent:
This is the truth. This is how it was said. This is how it was seen. This is what I know.
If a fire is burning due to fuel, it is not burning due to fuel, but it burns independent of the fuel. In other words: the fire does not burn due to fuel.
If a castle of cards is made, then a card is removed and that castle crashes to the ground, the crashing of that castle has not started due to the card being removed, but it started independent of the "removal of the card". In other words: the removal of the card did not cause the crashing of the castle.
If a red marble hits a blue marble and the blue marble moves due to being hit, the movement of the blue marble was not produced by the red marble hitting the blue marble, but the movement was produced independently. In other words: the hit of the red marble into the blue marble did not cause the movement of the blue marble.
If a truck crashes into a car and the car gets shattered to pieces, the car is not shattered to pieces by the forces the truck exerted on the car, but the forces were produced independently of the truck. In other words: the truck is not the cause of forces that shattered the car.
If you were to build a house, no matter what technology you would use, no matter what hi-tech materials you would use, no matter how you would built it, no matter what you would do, that house would be subject to decay.
If you were to knew and understood in its entirety why things are subject to decay, no technology nor any actions you would perform on things to eliminate their decay, would made things last forever. They would be subjected to decay no matter what you do.
If you destroy something, you destroy nothing. You can only dismantle an object to many pieces, but you destroy nothing. Everything rebuilds, no matter if you destroy it. If you were to destroy the universe, it would be rebuilt again. Everything in the universe is independent from everything. You can't destroy anything.
If you kill somebody, you kill nobody. You can only dismantle a being to many pieces, but you destroy nothing. All ignorant beings are reborn, no matter if you kill them. If you were to kill all the ignorant beings in the universe, they would be reborn again. All beings are independent from all beings. You can't destroy anything.
Etc.
I guess you're not bewildered by this nonsense. Good my friend, good. Does your understanding come from ignorance or from wisdom?
What is the cause of all this nonsense?