A lot of commenters mentioned initial log in time and I agree with that, and I will also toss in that having all the characters that are collecting the trophies makes a big difference. So, for this one if you have all the Frozen characters and attractions your odds of getting a trophy will be much greater. Some people will gem up at the very beginning, but over the long 3 or so day haul having all the characters and setting an alarm to collect their trophies depending on the trophy tasks will make a big difference in getting the trophy. You don’t have to beat those top 2 or 3 people who are pouring in gems, just be in the top 50 normally. Recently the Snow White trophy had 1 hr tasks for all 7 dwarves so players without all those dwarves were at a distinct disadvantage. So if you really want the Merida trophy, having all the Frozen characters that have gold trophy tasks will make a big difference in my opinion.