TBH I thought the quality of the passing from the back was ok as long as Vertonghen had the ball, Dawson and Rose in particular was another matter.
When people talk about passing problems, often the passing itself is an inferior problem to the problem of movement around the passing player being too slow, uncoordinated or just generally too poor.
With AVB our passing was very poor in the final third due to a visible lack of gameplan. Under Sherwood things appear more "free", but in reality as someone wrote to F365 the team has just losened up, making things visibly more lively up front, but also much less coordinated all over the pitch.
Under Sherwood I am extremely worried about the lack of confidence on the ball, when we win the ball in our third and try to move it through the middle third, runs are not made, one-twos not offered, the few good runs occasionally being made not seen and the few people who actively do look for space (hello Christian Eriksen) are very often overlooked in favour of either making overly risky passes to a heavily marked Ade or just running with the ball in really stupid places.
Definately need Sandro back as you say, a Modric kind of player wouldn't hurt either.