Not trying to insinute that the dog in question isn't a good producer, BTW--just can't understand why everyone always focuses on the male in a breeding, as if the female was just some piece of pottery that the puppies were 'baked' in for 60 days....
As it happens, Eliot has at least one significant advantage in his favor when it comes to breeding: he's got an 'open' pedigree, e.g. he has no linebreeding behind him for at least 5 generations, so it makes him a viable choice to with females that are heavily linebred, as well as those which have a similar open pedigree which would result in offspring with minimal linebreeding. This has probably played a role in why he's presently got at 287 offspring on the ground, the oldest born in 2008, according the the European working dog site.
Lena has a strong working pedigree to stand on, too, with her father Asko vd Lutter and the good bitches Connie Körnerplatz and Gimmi Abfuhr behind her in the motherline; the pairing of Eliot and Lena continued the open pedigree, which can be risky because you might find a good 'click', or the puppies might just be all over the place in structure, work ethic and so forth.
Given the bitches he's been used with, it would appear he's bringing something to the table, because the kennel names read like a "Who's Who" directory of the top working lines; Staatsmach has used him several times over several of their females, and there are some repeat breedings that you would expect must have produced something desirable...otherwise, why repeat the breeding (doesn't seem to have been a repeat due to no live pups on first one, either)?