In two of my previous lives:
1. Working for a long-haul cargo operator whereas the crews were contracted (paid) for 80 block hours per month whilst subject to JAR FTL's ... The majority, working away from their home domiciles, all they wanted to do was rack up the 80 hours as quickly as possible before legging it back to N. America, Germany or wherever, alas the JAR FTL's often scuppered their plans, all were 'self-employed' individuals but I doubt that any of them were paying tax/social security as I wasn't paying either.
2. As as 'in charge' of an agency flight crew recruitment, generally speaking we met two types of contractor flight crew, the genuine and/or younger naive who just wanted to work and we dictated to them the self employed nonsense and the 'professional contractor' who knew the loopholes as a matter of course and had no intention of ever paying tax/social security if they could get away with it.
Reading previously regarding McGinley, I worked for the previous agency that McGinley bought, I know the Ryanair contract that they entered in to because it was the one that I had previously worked, and Ryanair contracts, for an agency, were only worth entering in to if it was in volume, I mean a volume, rather than just a handful, of pilots placed.
Just another contract of that agency revenued EUR15,600.00 per annum per Captain and EUR10,800.00 per First Officer and these were typical of industry rates, on the other hand hand Ryanair dictated an agency rate of EUR8.00 per block hour per Captain and EUR5.00 per First Officer thus based on an absolute maximum of 900 hours per annum then just EUR7,200.00 per Captain and EUR4,500.00 per First Officer per annum ... not worth entertaining unless in volume!
McGinley didn't have that volume, Brookfield had the volume and with Ryanair's previous HR manager 'Declan' at the helm, Brookfield would jump through Ryanair's hoops because they were sleeping together, McGinley would jump through the hoops because they were always playing 'catch up'!