Interesting one Phil.The suggestion being that some of these b-sides were better than the a-sides which very well might be true but most of the a-sides were not hits either. As you say, a good comp though, in fact a comp of b-sides would be an interesting concept in itself.
A very common practice back then, the producer or record company chose the A side and in many cases from an outsider writer not from the group and in many cases session musicians used,but the group would get the luxury to write, perfrorm their own song for the B side, hence many so called pop groups B sides could be far more adventurous than the promoted A side. A real shady business, where producers would claim writers credits for royalties, I mean groups like love affair,the herd and the sweet were victims to that sort of action, where at some point they only got to choose and play on their B sides. Absolutely rotten business where so many young musicians where used and discarded, look at the likes of the small faces,badfinger and Bay city rollers, very popular groups who made next to nothing financially. Disgusting really. Record companies, managers and yes producers too all in it together!! I really hope it has changed since all those years ago. Even the Beatles and the who were on poor royalties for a while and contracts renegotiated when they started to have big success.