Fact: each individual rider responds differently to PEDs + training.
Theory: have a specifically skilled doctor long enough to track the blood parameters of riders as they train and dope. Once you have established their individual responses, you can pretty much set their regime and let them self-administer.
Personally I do not accept that Leinders was used team-wide, with Brailsford's tacit permission or expectation that riders would use him for doping per se.
I personally think Brailsford is anti-doping scandal, just like JV. As long as you fool the BP and don't get caught, he will love your results.
Brailsford doesn't have to have knowledge of what happened back in 2010 at the Vuelta. (cf 2008 track WChamps and Mr Team BC 50.3% Hct). First order of business is get it swept under the rug. Done. Txema was cremated.
With the road team, they have no results to date (unlike track team). So he asks the key team riders: who do I hire? He doesn't mention doping, and it's not on the agenda, but he acknowledges that riders doing what they're doing is failing (half the team are pulling out with stomach viruses and someone just died). He hires the right kind of doctor to make sure that (stomach virus stuff) doesn't happen again, he can essentially remain clueless and claim ignorance of anything else that is going on with that doctor when he's not looking.
Let's face it, they have not had a single stomach virus since, have they? So it worked.
I think it's more likely as they describe the Majorca camp. Every single possible facility is available: a chef, rooms to sleep in, coaches, medical staff, masseur/masseuse, mechanics, soigneurs, etc. Riders drop in and out and use the facilities as they see fit.
And for a while there, one of those medical staff was available, discretely, for specialised, personalised medical attention.