Another view of the two outlying stones, looking directly through the space between them.

Placing stones at some distance from circles is a very common feature at sites all over the country. A common thread that passes the boundary of stone circle type, region and age differences. Astronomical alignments are an obvious use for such stones but at the sort of distances they are placed at Gors Fawr no accurate readings could be taken from them.

The two large outliers, 
viewed from close up

Perhaps there is another use we have not yet thought of. I have already mentioned the likeness of the pair to an entranceway of some sort. They could have ceremonial or some type of symbolic use. Of course the whole social or religious use of stone circles can only be guessed at as the peoples who built them are now long extinct, and no modern parallels exist in surviving primitive cultures.