Castellazzi replacing Cesar isn't a big problem..
but the strikers are.. alongside the defensive leaks..........
1- if Leonardo is going to stick with the 4312 formation:
a) both Pandev and Biabiany should adjust asap to their new recruiting positions (CFs), or at least acquire one more striker to the first team
b) Leo must enhance the defensive mentality esp when the team goes scoring early and miss out defending setpieces..
c) if the players lack physical fitness to keep up with so many matches, some turnovers could be useful as we have good subs in all fields
2- i suggest he gives up that formation..
a) it's too defensive and exhausting.. and requires many adjustments..
b) the more offensive formation the less u receive goals as u push on the rival and prevent many setpieces granted for the rival team..
c) the less the demands of the midfield\sidebacks to go forward and score.. thus they spend less energy attacking and their defensive pressing becomes more vital
if Leonardo is seeking a possession strategy, the 4312 formation isn't much helpful, as it exhausts the midfield at most and thankfully our sub-forwards aren't good at keeping possession, the ball reaches them and goes to the other team.. then becomes the other problem, winning the ball back.. the midfield players are already tired to press on to take the ball, they're obliged to commit fouls and grant setpieces..
as i said, it's all wrong with using the 4312.. it needs a lot of adjustments and requires more workrate which is something u can't get from exact 12 players (11+Pandev) whose fitness and age don't help much esp with this full schedule situation..
Luka got some things right, Rafa did approach a possession strategy with a high workrate using 4213 formation, and the high defense line which is also mostly applied by Leo..
the tactical comparison isn't important atm.. but Leo's tactics analysis is
we really lack a decent striker to play alongside Eto when Milito is out injured and when we're playing 4312.. this is added to the previous issues.. as i said, imo, it's being used all wrong.. and Leo should figure it out asap...