The clock face gets misunderstood some times. The most important thing to remember is that the clock moves with you, no matter how you hold your guitar.
Here’s the easiest way to think about it. Hold your hand straight in front of you, fingers extended, so that your palm faces the floor. Your thumb is facing 9 o’clock and your pinky is facing 3 o’clock…That’s it!!! If you rotate your forearm so that your palm faces a wall, the clock has moved with you! So, your thumb still faces 9 and your pinky face 3.
The relationship of the clock isn’t to the guitar so much as it is to the player’s own wrist/hand. Since we all hold our guitars at slightly different angles and positions, thinking of the clock as relative to the instrument could cause confusion.