I think season two ended just about how they wanted it to end. I mean, I assume if they wanted Lindsey to have a sister, it would have been easy to work that into the show since there would have been no specific actress needed to play the part. And Spike was already contracted to Buffy, so I'm sure James was busy with that but probably could have worked in a little Angel screentime had they wanted him for more than just the flashback scenes in "Darla."