Thanks.
Before I forget : I'm french, give me a break
A good willing french newbie to whom the word "singleton" wouldn't have been a fisrt choice as an entry in the search engine (even though as I browse through the previous posts right now I see Randomizer used the term).
As Rent-an-Ihrno said, I find it difficult to care for a party of four. Plus I'd rather have one weak character going stronger and stronger (again, à la Elder scrolls) than four characters that constantly have to rely on each other.
However I've played Avernum some time ago with four characters and I had troubles staying alive while encountering foes so I had to ask for strong tips if I was to play with only one guy (one girl actually).