Hoes does this staff upgrade work? Does it replace central payout if you win, or does it replace team (side) payout?
Home grown talent? How does it work?
By reading the card, I'd say you are allowed to choose which one, with the only restriction you cannot choose to apply it to a payout you're not supposed to receive. So, if you win the match, you can change your zone payout, or the central payout with 3 fans; if you lose the match, you can change your zone payout; if you win the match unopposed, you can change any of the three payouts you would collect.
Hope this helps
What Julia said.
Page 15 of the Rules Book states that every highlight has three payment sections, one on each side and the central payout. The Home Grown Talent card says you can replace ONE payment section by three fans, so if you win the highlight you can choose which one you want to replace.