I tend towards the Captain's view. I think that interpreting the artifacts in Trellech into a full blown stone circle is difficult. I keep coming back to the "where are the stones problem". If the circle conformed to the general characteristics of other stone circles and had similar stones of similar sizes, I would expect to see more evidence of the other stones. If you consider the remaining stones as a part of a circle and follow the arc they would form, you are looking at a pretty big circle with many stones if they are spaced in a similar manner
I haven't seen any other stones in the village with similar characteristic to the three stones. The closest is the "druids altar" in the churchyard and this is a very different beast, being squared off and of a different material to the puddingstone.
If you take the example of Avebury, you can see that it was difficult to remove evidence of stones completely from a site and I believe that vestiges would remain of any major site.
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