That 0.03% may not turn out to be important, but it's nice to know.
While more beneficial for less experienced players that don't use preplanned routes, it's not unusual for groups to under or over pull, even in higher level dungeons. This leaves players with a miscount, in a position where knowing each creatures individual contribution can help them make more informed decisions to create a more efficient route.
Unfortunately, this count only seems to have the count in percentage form, and doesn't include the raw number of count which can make math a little harder in the moment.
Gotta get every last 0.14%!
Even for those organized groups which carefully plan their routes beforehand, having the enemy forces contribution built into the tooltip helps reduce the need for addons and provides a handy reference. Each creature's contribution to the enemy forces count required to complete the dungeon is displayed to a tenth of a percent, a level of precision which can even help verify third party planners. Unlike addons, there's also less concern with updating or breaking in combat, making this a good addition for all players, which is in keeping with Blizzard's intent to continue improving the standard in-game interface.
