This may be kind of hard to explain so i'll be as specific as I can.

In explore creatu have a additional 50 percent of finding their own kind of egg

So from what I understand since Drindian eggs are 40% rarity then in explore this should be 60% since 40%+(40%*50%)=60%

would that extra 20% be taken off of my chances to find other items or is it just a "this creatu adds extra eggs of their own kind"? 

Basically in explore if I were looking to find items should it be more efficient if I use creatu with no buff or have a low egg rarity percentage? or would there be no difference in the amount of items I find, just additional eggs?

I hope this make sense.