Gordy i agree completely, before i did any Traffic watch i got the 206 rating on my JAA licence
As far as 2 people logging the same time and neither being a CFI surely it would make sense that the person actually doing the flying hands on the controls should be able to log the time especially when they are a CPL holder.
Also only a small % of the time is actually traffic watch the rest of the time is approachs landing and take offs so for the CAA to discount all of it seems a tad unfair
Chester