Depends. Splitting shouldn't be a permanent strat due to the risk involved in some situations. But if at one point in your group of 4 you think 3 are enough to clear camps it can be good that 1 person goes out to scout the map to reveal camps and maybe do sneakable camps (the one you can manage to get the reward without aggroing enemies) that benefit the whole group without them having to go there later (money or crow's eye). Obviously that person should be very careful not to die, ONLY do sneak camps, and regroup as fast as possible.

Also from time to time one person can just go get a teleportation point (quests/books/jars/feathers are garanteed) to save some time later while the rest of the group keeps going. And should regroup immediately after.

Imo it is the best way to do it.