To clarify- if you have an incoming substituents in the metha or ortho position, there is a strong influence and if you have an incoming substituent in the ortho position there is little influence? (No. Since the sigma-complex has the formal positive charge distributed between ortho- and para-positions, the groups at those positions have the strongest effect on the reaction.The incoming substituent has almost no influence, because it attaches to an sp3-carbon with no formal charge - GS).