Do you have any sleep apnea problems? Also, Arnett/Gunson would probably see this as a CCW (counter-clockwise rotation) solution, so it might also require surgery of your upper jaw (rotation). Basically, it would appear as if your jaw is rotated too far clockwise (or from your pictures, too counter-clockwise) which would require rotating your entire jaw counter-clockwise (or clockwise in your pictures). Simply advancing your lowing mandible with a genio is usually insufficient and doesn't bring about facial imbalance. Hope that makes sense.
Generally class II/retrognathia without vertically maxillary excess traits (lip incompetence, excess incisor exposure, gummy smile, maxillary retrusion, etc.) does not indicate CCW as the occlusal plane tends to be flat rather than steep. In the OP's case, if upper is necessary, CW aka clockwise rotation would be necessary but again, that is assuming his maxillary vertical is deficient w/ flat occlusal plane.
It is actually incorrect to state that a mandibular advancement and a genio is "usually insufficient" as it's always dependent on numerous factors. A steep occlusal plane alone does not automatically indicate CCW. Just as a flat occlusal plane does not automatically indicate CW. Same with having a deep bite or recessed chin or gummy smile. Because each of these dentofacial issues by itself means very little in how one should go about correcting them or if it's really aesthetically or functionally necessary to correct them at all.
There is actually a young woman with a class II bite/jaw in Arnett's book (Facial and Dental Planning for Orthodontists and Oral Surgeons) where they used lower jaw surgery/genio only to give her an excellent result. They left her occlusal plane relatively sleep but avoided upper because her tooth display and maxillary projection were within the normal range despite not being optimal .
Would doing the upper marginally improve certain other issues, like flattening her occlusion and reducing her slightly excess incisor display? Probably but it does not guarantee her facial aesthetics would be any better. She also had the luck of avoiding any maxilla related complications and much easier recovery with less costs.
Here's another good example. His before pic isn't identical to OP but there has been decompensation of the upper incisors to maximize overjet pre-surgery in a case. His retrognathia is fairly severe like OP. His doctor wisely chose to just do a mandibular advancement and genioplasty which gave him great bite and strong profile.
Back to OP, without an x-ray and facial shots w/ smile, relaxed, etc, it's hard to give advice with certitude. There could be a need for upper jaw surgery too for full correction.
