I guess this is where we disagree as I would not class Steven Davis as an attacking midfielder in comparison to the other players I previously mentioned. When he's on his game he knits midfield and defence really well. Having Mane / Tadic in this role in midfield is completely different, which is why I disagreed with the original post.
Also, I'm not asking us to completely abandon a formation that as you say, has served us brilliantly for that period, just suggesting I'd rather 3-5-2 then an overloaded attacking team that throws the balance out. It would also allow Mane to have a free role around Pelle, which seems to be what we're trying to do with the current formation.
In regards to Cedric and his defending, surprised you can't see why people are questioning his defensive ability. It's obviously early days and not writing him off at all, but he's so far been shown wanting in his positioning and strength (not just against Lukaku) and I think its perfectly valid to raise this as a current concern.