This! It's not reasonable to announce two headliners in two consecutive days.
You need the press and if you do so at least one of the announcements, if not the two, will be compromised.
Last but not least, in what planet Smashing Pumpinks can sell 55 thousand tickets in a Portuguese festival? And you need the headliners to sell the majority of tickets. Smashing Pumpinks as solo headliners, in Portugal, only at Vilar de Mouros. Even Paredes de Coura with Lorde didn't sell out.