Yeah I can imagine that being what was planned.
It seemed that Fernandinho ended up doing his normal job on a number of occasions, probably because Gundogan wasn't, so that then looked more like the 'old' system we used to play.
You could imagine Fred in that system in either position & he couldn't really make a worse job of it than Gundo did, even if he joined us tomorrow & played tomorrow night.
But you could also imagine a new player, playing either role with either Fernandinho or Fred.
The right man, in either role, might leave us less vulnerable to the kind of calamity which happened at Anfield.
Of course it's not impossible that Fred, Fern plus A.N. Other might all play, in particularly tough away games, provided they showed they could do so without us losing attacking creativity.
That would be a tough midfield for an opponent to get through without losing the ball.
The addition of Mendy's attacking ability might also give that kind of lineup a different dimension compared to what it would be if we tried something similar right now.