First- What is the question? Next- what do you have three of? More information is needed like are these plumerias rooted plants or rooting cuttings or seedlings. Are you in the tropics (the big island) or are you growing plants under lights inside as most plants in the temperate zones are not growing right now. Also by growing do you mean getting taller than others or getting more leaves than others? If you have 15 random plumerias of different varieties, one can grow quicker than others as a cultivar. For example Cooktown sunset grows about two feet a year, and India is a tall grower, whereas Divine is a compact grower. If you have three of the same cultivar and one growes quicker, I would suspect it has a better root system or a better position in its environment (I have two plants from the same cuttings planted the same day in a hedge. The shady end plant is 5 foot tall while the sunny end plant is 9 feet tall). Without more info, I am just guessing.

im a growing them under lights i just got them in a trade, im not sure of the type they are just realy thin and tall