I don't know why they didn't come out and just call them 'we couldn't think of an actual connection box sets', but there you go. :-) I suppose i9t does at least continue the DW tradition of being random and weird.

They should start selling New Who seasons paired with old ones while they're at it...

I suppose Spearhead was one of those that would have been definitely up for a 'Revisitation' - and one that would tempt me to buy again, if shiny enough - but yes, it is a bit of a cheek. Maybe I am wronging them - maybe they will start making them available separately presently, but... erm... !?