For those of you who have not checked out the test server, there has been a significant change to how explorers bring back event resources. I like to view it as a...
... to appease the masses.
As it stands now {subject to change at a whim} explorers will always bring back eggs. Yes, every search you send results in eggs. An unbooked search brings back the following.
Short: 2 or 4 eggs.
Medium: 3 or 6 eggs.
Long: 5 or 10 eggs.
Very Long: 10 or 16 eggs.
Prolonged: 12 or 24 eggs.
So with no books in any of your tavern explorers and sending them out as soon as they return yields you the following if you always get the low drop.
Short = 8 eggs per day
Medium = 6 eggs per day
Long = 5 eggs per day
Very Long = 5 eggs per day
Prolonged = 4 eggs per day
Keep in mind that hopefully you will not be around every time an explorer comes back from a short search. Anywho for previous events it all sort of balanced out within a percent or so but now sending your explorers on the shortest search you will be around to send them back out for is unquestionably the path to take.
If you are curious, here is my math with how my explorers are booked...
Spoiler
Overall I have an army of 19 explorers and doing the math it looks like I can expect just short of 400 eggs a day... which is what I was getting in presents during the Christmas event. Looks like this will have little impact on anything other than making people not complain because their explorers brought back nothing. Just remember that getting all the generals, buildings, and the five scenarios you need for the achievements will cost you nearly 20,000 eggs.
So those are my thoughts on the issue. Hopefully it is more helpful than a waste of your time. Feel free to correct my math or add in return rates more reasonable than being awake and online every hour and a half sending your lucky on a short search. Once again, this is how it stands now and who knows what it shall turn into.