3-1 is fine. I have played that and in some situations it is superior to the 2-2 line. Firstly as someone mentioned beforehand, 3 luxrays really helps your start and is pretty ideal for this deck. Also against Gyarados, you want to swarm luxrays, it is a tad harder when you only have two since Gyarados will just tail revenge it next turn.
I use 2-2 as in all other matchups, you just have a bad draw when you draw into a luxray gl midgame since you don't have anything creative to do with it. Also since you don't run claydol, it will just clog up your hand etc.
But 3-1 is fine and is still very playable, don't be put down and it is still unlikely to have a luxray in your prizes anyway.