It buffs nothing, Monkey. You max out at Tier 2 for each of the Madden Scheme Chemistry slots at this point. That's why there are no Tier 3 bonuses listed. Quite frankly, the game should not allow you to purchase a Tier 3.
So, if I'm you, I'd choose a different Madden Scheme Chemistry with your third slot. I currently have Tier 2 Madden Pass Defense Chemistry, and I'll be getting Tier 1 Madden Passing Chemistry when I have enough Series 2 Trophies for Series 2 Madden Coach.
It buffs nothing, Monkey. You max out at Tier 2 for each of the Madden Scheme Chemistry slots at this point. That's why there are no Tier 3 bonuses listed. Quite frankly, the game should not allow you to purchase a Tier 3.
So, if I'm you, I'd choose a different Madden Scheme Chemistry with your third slot. I currently have Tier 2 Madden Pass Defense Chemistry, and I'll be getting Tier 1 Madden Passing Chemistry when I have enough Series 2 Trophies for Series 2 Madden Coach.