On one of the early jobs we did we had to use noggins because the 'kit' came with the wrong roof anchors, that were more suited to a plain tile than a Marley type concrete interlocking tile. It would have been a minor miracle for the gulley in the tile to line up with a rafter and it transpired that none of them did.
With no time to send the things back and wait for replacements we had to improvise, which meant installing noggins for every anchor. Each noggin was fixed through the rafters with 3 heavy duty fischer power fast woodscrews at each end but I still wasn't happy with how much play there was on the fixing once it was in place. In the end we reinforced every noggin from above with a length of 9mm marine ply spanning between two rafters and screwed down onto the noggin and the rafters, this made for a very secure fixing with virtually no movement at all. It took much more time than it should have to get it right, and that was last 'kit' we ever used and the last time we ever used that supplier. There probably is an easier way but it needs to be solid.
The bracket method may make for a better fixing, but haven't every used it so can't comment.