Counting Clair de Lune

I don’t think it’s wrong, but it is a lot of work! All that 123/12 is crucial for Brahms, but Debussy’s rhythmic language here is more gestural than precise. I would count three beats to the bar at first and play a little with the shorter notes 

He really wants you to make it obvious that the piece does not start on the downbeat. So the rhythm police won’t come in if that first chord is more a sixteenth, but they will stop by if it’s a full eighth with an accent. The triplets to eighths are a signal to take a lot of time and the notes don’t  have to be even.
 

Later, for the piece to flow, it’s really one beat to the bar with the melody  dodging in and out of the conductor’s baseline like a jazz singer. 
 

here is a piano roll of Debussy playing it. However much rubato you thought to use, it wasn’t enough.

https://youtu.be/Yri2JNhyG4k?si=WPPKMTl9gnuZSTUZ

I'd say counting that way is perfectly correct. I think the challenge is essentially to feel both rhythmic layers simultaneously.