Not disagreeing with all the comments, just a bit p'd off that just when one has learned their new system they seem to change it, certainly every - admittedly infrequent - time I've used S'west it as been different and caught me out. I guess "when-in-doubt-read-the-instructions " is the answer !
Tho' there is no alternative to ensuring that young families sit together, it seems that providing one has a brood of children with one, then all systems are by-passed anyway ! Families with kids get on first. If S'west are an example of Capitalism at work, as suggested, then surely there is an opening for someone to establish a "Rent-a-Kid-for-Travel" business ?
As I first mentioned, yes, sometimes I have a choice so can give S'West the Heave Ho, but not always and they do run a good service apart from this boarding battle - last time they even paid me not to fly my booked service by rewarding me with a cash voucher for future travel, to fly 2 hours later !!