I haven't seen it mentioned here but it should be noted that the lashtail raptors for second part of Raptor Mastery and The Defense of Grom'gol quests are the same raptors. If you wait to do The Defense of Grom'gol until after you get part 2 of Raptor Mastery, you will be completing 2 quests at the same time. It will cut down on XPs for fighting less mobs but it makes things go a little faster.