LHN, in 2011 some ex colleagues joined NAS as DEC and were categorically told that after 2 years as a " contractor" they could become CORE but only as FO, however, keep their seniority, reason being the the CORE group had a preserved seniority list, in my opinion, that's "kind of "fair enough. Two years later they were told there would be no more CORE conversions from contractor and their agency was changed yet again. The comments you make relate solely to the privileges of the CORE group and do no represent the interests of the majority of crews where the real expansion has occurred outside of the Scandi countries. During the industrial action from the unionised group pilots from other bases, mainly Spanish, were rostered to " cover flights", this itself is divisive action and shows patently their is little or no cohesion amongst the pilot groups. The argument generally was that non unionised pilots could not reasonably support a strike they were not "officially" part of, these same pilots, if they refused the duties would have their contracts terminated as they were not " protected" by the stronger employment laws relating to CORE pilots. In the ideal world, the whole pilot workforce would be one amalgamated group, but to do this their would have to be compromise by the CORE pilots, are you going to be the first to throw yourself on your sword?
Back to the OP, the acquisition of OSM shares must surely reduce recruitment costs as commissions become internal wooden dollars, however, the " arms length" relationship between agency and employer is severely tested with this model and as we say " poacher becomes gamekeeper"