I’m suggesting that instead of getting only one species of epic dino for a month, you could have a selection to choose from. Selection could be 2 to 3 dinos, just like the dartable theme dinos are. You could make the choice every day, so if you just need a few more dino A’s, you could choose it on a few days and then concentrate on dino B for the rest of the month.
With this system, the epics would be circulated on the daily system much faster so you could wish to gather eg. brachiosaurus maybe once a year.