The remaining oils in your kit are blends. Gary Young spends an extraordinary amount of time, energy, and research creating these blends. With that said, they are formulated to work in a specific way and it is often not suggested to mix blends together (however, Thieves & Purification seems to be an exception). It is not harmful in any way, but it could reduce the effectiveness. You can freely add singles to blends, however. Notice 2 of the blends are vitality oils as well and are 2 of the oils I use internally the most often because they are so incredibly effective!