Anyone who cared to do so could troll through my posts here on PPrune from some years ago to see I've sung this song about losing and lost handling skills before... (and was howled down very firmly by those who told me that the days of hand flying were long gone).
I did a licence renewal sim. some years ago - close to 15 years ago, as I recall - where the checkie gave us, among other things, a double ADIRU failure, leaving us with what amounted to a 250 tonne Cessna 152, i.e., no autopilot, so speed tapes, no FMCs, no flight directors, no EICAS, no magenta line - pretty well no nothing except for (still fully functioning) basic flight instruments.
After dealing with the problem, the decision was made to RTB, but we had to jettison fuel before landing, so I did what has pretty well always been my habit in non-normal situations, handed over to my (in this case, ex-cadet) FO and had him fly the aeroplane while I handled the checklist, dealt with the purser and passengers, as well as ATC.
But it soon became obvious that this wasn't the way to go in this case. Within minutes, I looked up from the paper checklist to find what was quickly developing into a rather extreme unusual attitude.
The FO simply couldn't maintain straight and level flight without 'all the toys'. I had to reverse roles and have him handle the checklist - and I have to admit, my own hand flying, distracted as I was keeping an eye on how the non-normals were going, wasn't all it could be.
A second incident in that same sim. session is worth relating. On finals, the basic flight instruments started going all over the place - airspeed increasing, vertical speed changing rapidly, and all with no input from me.
(Of course) you're all saying: "What a ********! He's describing classic windshear." And you're all right. With the ADIRUs out, all the EGPWS systems were inoperative, and I'm embarrassed to say (the point of my story) that it took me far longer than it should have to recognise the raw data of a windshear event and to initiate a go around. For how many years in my sim. sessions, I'd been reacting to the very 'in your face' aural windshear alert, which was always very much in evidence before (or as soon as) the flight instruments showed any variation.
In the unlikely event that you ever find yourself with 20 or more minutes to spare at the end of a sim. session, I would highly recommend asking the checkie to put you this situation and work your way through to an approach and landing (preferably with a go around thrown in - [and remember, you'll need to have noted down a go around N1 from the QRH long beforehand - no bugs without the ADIRUs). It achieves what all sim. sessions SHOULD achieve - the trainee going away having learned something.