Which needles for hand stitching - Sewing Leather

I’ve read that size 4 and size 5 harness needles are the most common needles to use for saddle stitching. I ordered some CS Osborne # 517-4 and 517-5. Did I get the wrong needles? What should I have gotten?

hand stitching taper leathercraft needle canvas

Leathercraft Tool 120mm Brass Handle Leather Sewing Awl Kit, with 3 Interchangeable Needles, for Hand Stitching Leather

Owden 12Pcs Leather Hand Sewing Needles Professional Small Eye Design for Leather Hand Stitching Needle. 2 Sizes and Each 6Pcs.

Which needles for hand stitching - Sewing Leather

Miscellaneous Sewing Needles: Leather Sewing Needles

Upholstery Restoration Kit Leather Craft Tool Kit Leather - Temu

Leather Sewing Kit Leather Needles For Hand Sewing Heavy - Temu

Hand Stitching Leather with an Awl and Two Needles - Don Gonzales Saddlery

Weaver Leathercraft Hand Stitching Kit - Includes Every Tool Needed to Hand-Stitch Leather - Stitching Pony, Needles, Thread, Stitching Chisels, and S