Each breed is apparently worth only 1 point no matter what. If you use all three breeding locations, then considering most results are in the 8 hour range, you can expect ~27 points over the course of the event without accelerating breeds. And that still requires spending significant gems speeding up the hatching to keep pace with the breeding.
That would be 80 orbs, which is potentially interesting (i.e. one star) to people who have one already if the global goal is met (a good bet, it's 1/3 of the way there with 1/8 of the time elapsed right now) and they recall the dupe. Getting enough to summon if the global goal isn't met, or to empower to one star if you don't already have one and it is, requires 50 points. That's a LOT of gems. And for an Epic, not exactly a powerhouse.
Accordingly I can't see that it makes any sense to do anything more than the minimum 4 to qualify. Very badly balanced event IMO.