Top 5%.
I have explained it with logical explanation to you in another thread multiple times, someone even backed my theory with experience from beta but it seems you keep ignoring it:
How many more people do you think will be joining? Most of my alliance teammates said they are going to opt out because the don’t want to have 5 feeder slots locked for 6 days.
Who have a lot of 1* heroes but don’t have 3* heroes to compete in 3* tournament??? Newbies??? You need to be level 14 to enter, by that time you won’t even relly on 1* for map. And most importantly, how many newbies are there who is going to participate??? Most newbies only use 1☆ in their first few days (if not only a day) playing.
Rather than more participant, it will lead to less participant which mean the chance to enter top percentage is smaller.