as to the argument of a mongrel being able to carry the title: livestock guardian dog,a section of a website I found, pertinent info highlighted:
Mongrels
Mongrels are used extensively as livestock guarding dogs by the Navajo. Black and
Green (1985) pointed out that their method is a cheap, low labour intensity and
readily accessible form of livestock protection which could be employed by other
ranchers. Coppinger et al (1985) have emphasised that no evidence was provided
that any type of dog can make a good LGD given sufficient training and postulated
that mongrels are likely to make better LGDs than most pure breeds except for
Old World (Eurasian) dogs bred specifically for the purpose because
hybridisation disrupts eco-specific behaviours such as hunting sequences which are
undesirable in livestock guardians. However, a six year study in Bulgaria
concluded that hybrids of the native LGD Karakatchan with other traditional LGD
breeds (Caucasian Shepherd) as well as St. Bernard and Newfoundland did not
have the ability to guard livestock (Tsingarska et al 1998).
Black and Green (1985) mentioned a few other observations of mongrels used as
LGDs: a large, 34 kg mongrel dog working with a flock in Turkey (R. Coppinger
pers. comm. to Black); Orbigny (1826) observed a large dog that both herded and
defended members of the flock from large avian predators and human intruders in
Uruguay; Bendure (1948) also described the value of a mongrel dog in predator
control. During visits in August 2001 four mongrels were seen in use as LGDs in a
flock of sheep herded in Retezat National Park, Romania and several mongrels
(together with Karakatchans) were seen guarding sheep and goat flocks in the
Eastern Rhodopes of Bulgaria (R. Rigg pers. obs. 2001). Landry (1999b citing V.
Guberti pers. comm.) mentioned the use of mongrels in Italy.
the link to the info:
http://www.canids.org/occasionalpapers/livestockguardingdog.pdf
Ummm...so doesn't the site I quoted refer to mongrels as potential LGDs?