I was under the impression what you describe kanisha only applied to the long tailed sheep, with northern shorttailed ones coming across the north
"A series of waves of development have been proposed with the ancestors of the domestic sheep considered to have been in several species and subspecies of Mouflon. Poplin Ryder and Lauvergne each had their own theories for the waves and centre of development. The study by Kantenan et al (2006) used mitochondrial DNA testing to produce a distribution map and demonstration of population expansion with the mediterranean mouflon as an early domesticated ancestor of european sheep. ( There is an undetermined ancestor of the mediterranean mouflon if it is considered a feral domesticate) but that there was a second lineage with a concurrent development of domestication following a migratory route through Russia into the nordic countries.
A study by Palmarini et al (2009 )
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145132/ used retrovirus integrations to be able to demonstrate with greater accuracy the migratory development of sheep and in doing so confirmed the wave theory and primitive factor.
The wave theory suggests that primitives ( short tailed breeds of sheep) were in the first migratory wave. "
Commenting on this study Insciences organisation wrote " Interestingly the orkney sheep ( north ronaldsay) are more closely related to nordic breeds in scandinavia while soay are linked to Mouflon, providing intriguing insights into ancient migration routes" 2009.
The study also appears to demonstrate that Ryders earlier classification of european short tails into several groups placing the Ouessant sheep in a small group of south western short-tails may have more relevance, rather than grouping them altogether as north european short tails.
Loosely paraphrased from a study on Ouessant sheep by myself 2011.