Personally I disagree. Having three at the back (or five when we're defending), does give us more coverage across the middle. Look at how many goals we conceded where players got in between the two centre backs. Particularly notable when the CBs were pulled wide to cover for a marauding full back. Now there is still cover in the middle when that happens. It also gives both full backs more liberty to attack as a pair.
As for the MC goal. Ridiculous to blame Ramsey. If giving the ball away on the edge of the opponents box leads to a goal for them, it's not the fault of the person that lost the ball. All teams will lose possession in these situations.