The listed inseam and saddle height do not match-up. A common saddle height for someone with an 86cm inseam would be around 76cm, not 79-81cm. Makes no sense at all.

The M or L sizes could both be made to fit the same. The 145mm head tube length is on the short side for a 76cm saddle height, unless you know that you can tolerate a saddle to bar drop in the 7-9cm range, or you're willing to use a flipped-up stem. That might make the size L a better choice, since the head tube is only 9mm taller. It will require one size shorter stem. To deteremince the stem length difference, you have to compare both the TT lengths and the seat tube angles. The steeper angle on the size M increases the reach by about 5mm, so the difference between them becomes 10mm, not 15mm.