I don’t know much about drones but I have a pilots license and in my opinion it would be extremely hard to have forecast winds aloft accurate enough to reach a target hundreds of miles away with only time and vector information as the inputs.
They aren’t ballistic missles, going thousands of miles an hour, they’re going to be affected by wind.
They’ve got to be using GPS positioning too I would think. Why wouldn’t they?
And unlike with early ICBMs, precise accelerometer and airspeed inputs can provide quite good measure of lateral forces.
Were they had a satellite, or used HF comms, somebody would've either timed the satellite, or spotted the HF signal long ago. And there were no sign of a huge satellite dish one needs to communicate to satellites in high orbit in found drone remainings.
I doubt that those existing Yemeni drones use any radionavigation or remote control to begin with, as it looks to be a certain overkill for the task.
All their targets so far were big stationary targets, and there are all signs that they all use simple time (and not position) programmed maneuvers.