evolution of a colony

This year's foxes have puzzled us since we first saw them together. In previous years we first saw cubs above ground in early summer, like 27th April (2003) or 8th May (2004). Of course we always watch and listen eagerly for signs of a new fox family, though this year there had been little to suggest it. We were resigning ourselves to another summer without cubs like last year. And then this bunch showed up.
Earlier this year I had been logging sightings of two foxes, regularly seen, sometimes together. One was skinny and pale and was named "Bootlace" from the tail, which was hairless with mange. This is a common look with mangy foxes. I squinted and peered but never got a definite look to sex it, but thought female. However no nipples visible, and they usually are in a recently delivered vixen. The other one was certainly male, of stocky build and large wide head. I called him "Broadhead" and I think he is still with us. Broadhead and Bootlace behaved very like a mated pair but we never saw a cub with them. Surely it could not be a second year of sterile mating? Cubs could be elsewhere of course.
And then, on the 31st of May, we see three foxes in the garden, next door.
*I should perhaps explain at this stage that virtually all of the sightings here recorded are in the back garden of our next-door-neighbour, Mary Martin. We get a ringside view from our bedroom window. Now read on:*
The three were; Broadhead, as before, with his grey bib and white blob of a tail-tip. Tipless, who seems to be the same fox as we saw last August, 2006, already adult then; he has no tail tip, grey bib, bright amber coat, 2 small patches of mange on haunches; and finally, one with a whiter bib and a pointed narrow tail-tip, posibly female, possibly adolescent. She (or he) is Pointer.
The puzzling thing is, this was the end of May, and none of these was a cub of this years batch except maybe Pointer. yet they are clearly a fox family group and have been seen greeting with the classic double-gape, and grooming each other.
The possibilities are;
Broadhead is the father, the mother was Bootlace, now dead of mange, Pointer the only cub to survive. Tipless would be an uncle? Not usual. Related foxes do help to rear orphaned cubs but that would normally be low-ranking, unmated females.
Maybe all three are sibs? Pointer the sister of Broadhead, helping to rear his family after death (presumed) of Bootlace? They certainly act like sibs, sometimes "getting up a game" by pawing the ground and crouching, just like domestic dogs who want you to throw a ball for them. But the two males are too grown-up to be this year's litter and they wouldn't be still together after a year, not two males, I think. I could be wrong about that.
Anyway, Nature is now taking it's usual course; Tipless spends a lot of time in Martin's, sleeping the day through on the lawn, under a tree, even on the footpath today. A second fox is also seen, just a brown patch and a pair of ears in a corner. Tipless is strong and experienced, and he is claiming this turf.