Maybe someone did the calculation but here is something from me.
Let’s assume we will have one event every week to gain emblems. In the event we have two classes out of 8. This means that once a month we will get 18 emblems for a class. If we receive another 12 emblems for the same class out of chest loots including color chest Titan battles and War chests then this means that every month a F2P player will receive 30 emblems. In order to fully ascend a 5* hero you need 1515 let’s say 1500. So 1500 divided by 30 totals 50 months this is over 4 years. I will say that this is wrong seriously wrong. E&P please fix this I would suggest you either drop the required emblems 4 times or increase the drop rate by 4 times (1 year for F2P is me being realistic where you have offers for the customers ready to pay and make this for 3 months instead of an year).
Please think about it or I foresee lots of frustrated players quitting the game.