FWIW, a clutch fans does not have any clutches. It's more kin to a torque convertor. There is a viscous fluid in side that couples inner driven impeller to the outer housing the fan is attached to. The non-thermostatic ones have a constant slip rate. The thermostatic ones vary the slip rate with temperature, i.e. higher temperature less slip.
The typical failure mechanism is the seal will fail and the fluid will leak out and the slip rate will increase until it can't keep the engine form over heating.
I had one that the bearing failed on and it allowed the fan to wobble which created some vibration and also essentially locked up so there was almost no slippage. But, there was no danger of the blades seperating and in my case it was far enough away from the radiator there was no danger of the blades hitting the radiator.
The flex fans have a much much higher incidence of failure where a blade seperates from the hub.