I was talking to someone who has studied that period, and he came out with some interesting information.
The shepherds may well have been the ones that were in charge of looking after the lambs being bred for temple sacrifice, in particular they may have been taking the sheep towards Jerusalem for use as the Passover lambs.
They had to be pure, unblemished - so there would also have been Temple Guards/priests watching to make sure that they were kept as pure as possible.
Two things from that. Firstly the symbolism of the shepherds being first to see Jesus who became the "Passover Lamb" for the people.
Also Jesus being swaddled and laid in a manger - apparently they used to do that to the pure lambs to keep them from being hurt or damaged in any way before they were sacrificed.
The Shepherds would have appreciated the symbolism of this.
But also what occurred to me, is that if there were temple guards and priests there when the angels appeared, surely they would have seen the angels too. We have no mention of them going to the stable, but even so, surely it would have been something they told to other people when they got back to Jerusalem. And when Jesus came into Jerusalem on the donkey on Palm Sunday, some of them must have made the connection.
You remember how the Priest said that angels appeared when they were watching the lambs thirty years ago? The shepherds saw the baby the angels said about and this must be the same person!
May be a load of rubbish, as I've only heard this from this person, but I rather liked it.