Let's say that the Player Character has a +4 in Fight. He's confident that he can take down two Goblins with a single action, so he decides to roll against both of them. The results are as follows:
PC divides his shifts in half, giving 2 shifts to each and succeeding by 3 each. That's two successes with style. Does he deserve 2 boosts?
He managed to get two successes with style, even though he has split his result in half. That's an amazing display of overpowering combat prowess and he deserves to get those boosts!
When you succeed with style on an attack, it works like a normal success, but you also have the option to reduce the value of your hit by one to gain a boost as well.
after Fate SRD
So, to get each of his boosts he has to hit for 2 shifts instead of 3. That balances his double boost bonus. He can also choose to hit one goblin for 3 shifts and another one for 2 shifts with a boost, or resign from getting any boosts altogether.
