Change condition in advance instructions.
At set numbers of goal difference from (+5 to -5) to (+4.5 +3.5 +2.5 + 1.5 +0.5 -0.5 -1.5 -2.5 -3.5 -4.5).
It easy to use mathematic solution
(Your score) - (Opponent score) : Less than ( < ) or Greater than ( > ) : Goal difference
And can you add more player substitution from 1 to 3 in 1 instruction?