elysisone: Those witcher at the intro are, without any doubt, Berengar and Lambert.
Lexino: Not Berenger, its Eskel, you can see his face scar
QFT.
On the topic:
It's not a big surprise, imo. It was a good idea to have them in the first game, to introduce players to what a Witcher is and give them some general background about the profession and its history.
But in the books they don't appear too often either. It's more of a loose community, no strict guild or something, at least lately (ever since there are only so few left. Don't know about the times before). They (used to) meet every once in a while - mostly once a year during winter - and else scatter throughout the Northern Kingdoms in search of work. TW1 has taken place one month before TW2, so a year didn't pass yet and there's no real reason for them to meet. And not having accidental meetings is more believable than having them, given the size of the Kingdoms.