I really do think that the changes we make have an effect, sometimes we don't know what that effect is, better or worse, until you try it. I am fairly sure that the defensive/normal/attacking choices make a difference, they do for me anyway.. perhaps your results will vary. The red arrows do seem to make players more attack minded, but I have no clue what the blues do. The tackling choices for me do seem to make a difference (usually in yellow cards ) I usually notice whatever effect takes about as long as a sub to go into play.