abdul rakitic

hello, I have started a save as the mighty Blaugrana in fm24, furthermore in the madscientist's 2008 database. I am now in December and I have been changing the tactic employed by me throughout the save, as I have not yet achieved my goal, being implementing the short passing, position-based tactics used by Pep in his early Barcelona days. I have had 2 main issues - the midfield roles, and Messi. I am employing a midfield of Márquez as half back, Iniesta as an advanced playmaker on attack and Xavi as a centre mid on support. This ties in directly to the Messi issue - I am sometimes unable to dominate games (>60% possession). Could I change these roles in any way to improve that? The second issue is the Messi one. I have tried like 5 different roles on Messi now, usually returning back to Trequartista in the striker position. What role would enable me to use Messi as a 4th man in the midfield (in a diamond midfield, such as the one used during the 6-1 win against Atletico Madrid in 2008), while also enabling him to score goals? I have tried playing him as a false 9, however in that case I am not sure how I should manage the 2 "wingers" on his side. Thank you, below is the tactic that I am currently using - it is quite inconsistent, as I just beat Chelsea 4-0 in the CL group stages, however I fail in other cases.