Train 1st speed to 9-10* and you will be capable to beat 9* as I did in the cup some seasons ago.... page 34-35 of ma teamshowcase have the cup +3 or +4 levels results...

Ma theory defend that the internal %'s of effectiveness can not be modifyed in a big sense and really a player with 5* will show the 90% of what he can do, but the anticipation is another thing, and despite the betetr or worst %'s of effectiveness you can beat a team by having same anticipation, and you can have that by training speed, that means all cones to phisicall.
And till here ma theory. lol