My Lands: Black Gem Hunting

Does the speed that your explorers go out really matter?

I've been sending my explorers out on slow and it says 2% chance of death, But I've have 4 deaths in the last 8 explorations. Is there something that might cause my explorers to die more frequently or should I go to Vegas with this kind of luck?

Speed is the only reason. However I can tell that the more explorers you have, the less they die.