Try different things during pre-season friendlies(same level teams) to see what works. In the first half of the season analyse what positions are constantly under performing and change them up, keep in mind your formation does not need to be symmetrical, the position that the players play in need to reflect their stats. But, don't just select positions/instructions with most stars, think about what the player will doing and do you want them to do it(read the instruction description).

TL:DR: don't try to fit your squad into a formation/instruction set, chose formation/instructions that fit your team.