Hi Q8canuck.
I just noticed that your previous post got buried in the by another discussion in progress :oops: . I deleted the duplication and responded here.
Glad to hear that your “hubby” is sleeping well on the new mattress … Congratulations on your new mattress purchase 
… it looks like your side needs a bit of fine-tuning and it’s good that you had the foresight to order from a manufacturer that has good exchange policies.
I am not sure I understand correctly the configuration you have in mind but I tend to agree with your husband that the layering arrangement you mentioned may not work in your case. M/M/S on your side (from bottom to top) wouldn’t be adding the extra support that you seem to desire but instead would have just the opposite effect so I’d be concerned about your spinal alignment and support …. also on your husband’s side an F/F/S configuration would most likely make it too firm for his needs as well.
As mentioned above there are some mixed messages in your descriptions regarding your support/comfort needs and you’d want to determine if it is the lack of support, comfort or both that causes the shoulder and hip soreness. Your initial assessment of adding more support seems to be pointing in the general direction as typically a more “generous” weight range sleeper would need both firmer base layers and firmer comfort layers to make sure the mattress keeps them in good alignment in all the sleeping positions. You may wish to revisit the info about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here which may be helpful in clarifying the difference between “support” and “pressure relief” and “feel” as you go through this identification process.
Typically shoulder and arm issues can come from a mattress that is too firm and puts direct pressure on the shoulders, the shoulder blades, or on the back muscles and can also cause soreness or numbness and tingling in the arms or can often come from postural issues as well. There is some much more detailed information on shoulder and arm issues in posts #2 and #3 here and I’d make sure to pinpoint the type of comfort/support (primary/secondary) issues that may contribute to your soreness and also assess the pillow you are using as this can be a big contributor as well. Hip issues, for side sleepers especially, can be caused by a comfort layer that is too firm or too thin where you can feel the firmness of either the sleeping surface itself or the support layers “through” the comfort layers. These are pressure point issues. In some cases though another reason for hip pain may be a mattress that is too soft which can cause your hips to be out of their neutral alignment and sink down too far which can hyperextend the hip joint and can lead to a burning feeling or pain from joints, muscles, and ligaments that are stretched beyond their neutral alignment. This would more of an alignment issue except instead of spinal alignment it’s about joint alignment. I’d also make sure to check the pillow issue and verify that the bed has good central support and if it is not sagging under the weight of the mattress and the people sleeping on it.
You may also wish to peruse some of the forum posts and threads about mattresses and higher weights and a forum title search on heavy (you can just click this) will bring up many of them. Some examples include post #2 here and post #2 here and this thread
Of course, your first best source of guidance is always coming from the manufacturer/retailer of your mattresses who can give you suggestions for their layering designs based on averages of other customers that are similar to you, but feel free to add your thoughts and clarify some of the issues I mentioned above and I’ll do my best to assist you.
Phoenix