The “Industry Standard” is that there is no standard.
I have struggled with the same head scratching confusion, having bought Arrowind, RSM, Turnigy, and Cobra motors for one reason or another.
Since I’ve had great results with Cobra motors I decided to settle on that brand, and I have my four favorite sizes that I know will fly a given size airplane.
I’ve also settled on 4S batteries (although I’m open to 5S if needed) and Castle Creations Edge Lite ESCs.
Timers are a different story. I find it hard to choose between KR or Hubin timers, they both work very well and have good features.