Wool does take ages to break down under normal circumstances and if you spread it on your veggies too soon and then use a rotavator, it gets all tangled - I have done this
I am slightly concerned about the use of bracken - are the spores not carcinogenic? Presumably you would have to harvest it at a time when there were no spores.
Would it work to layer wool and bracken, both unchopped, then leave them in a covered heap to get on with it for a few years?
I would rather use wool in the garden in a number of different ways. Really daggy bits can be spread under fruit bushes for the mucky bits to wash down to the roots (while remembering about the rotavator bit at a later date). Or the daggy bits can be soaked in water to make a yummy liquid manure for dilution and use on the veggies, then the wool goes in the bottom of the compost heap. Whole scruffy fleeces which are no use for anything else can be spread over the compost heap to keep the warmth in - after a few years of use they are then put in the bottom of the next heap and they will eventually disappear. They can be used to line hanging baskets or in the bottom of tubs (to stop the soil falling through the holes). They can be used in the bottom of potholes before the stones go in and they help to bind it all together (stone felt)
Bracken can be harvested, dried and used as bedding for animals - but what about the carcinogenic spores?