When you said the new limit will be 15 for new hero fragments it sounded amazing but, of course, there was a trick
So, in order to 15 real fragments per day, you must:
-Be able to defeat coop raid 90 level
-Reset at least once per day (80 gold) the raid
-Have enough luck to get 5 fragments in each of these raids. Otherwise, you’ll have to resent again (180 gold per day).
If you are not strong enough (I’m level 90 and sometimes I suffer a lot with helios 85) you’ll have to reset at least twice (with a lot of luck) or even three times (and play it, of course).