I lost my rake/comb.....don't know where, don't know when and I don't think we'll meet again some or any day. Replaced it with a leveller.
Always pin leveler with fibrous screed and comb or rake with standard. Like you said Sandy the rake or comb will collect the fibre particles and drag them out of the screed and clump them together thus causing it to loose its cohesive strength, pin leveler only has two pins so no problems there.
Thought the pin leveller has 4 pins, the one I looked at did, is there different ones? Which is best as getting one in may