Confused about pleating to the sett

[Mainelydad]

I'm having difficulty figuring out the number of pleats that I'll need. I'm attaching a photo of my tartan which has a sett of 5". I've placed pins to show where the pleat sections will fall. Each pleat ends up being 1".

So here's where I get confused. If I'm pleating to the sett, am I correct in thinking that the tartan should be accurately reproduced at the level of the fell? In my case each pleat would be 1" wide at the fell. I've split my hip measurement of 43" ( 21" - apron, 22" pleats) So am I correct in thinking that I can only have 22 pleats? That seems logical to me. The size of the sett and the width of each element dictates how many pleats I can have.