It is impossible to expect anything other than a tribal militia at this point. Even now there is no SNA, just a Hawiye militia based in Mogadishu calling itself that. Your best hope are clan militia that clear out their clan territory while receiving their pay through the federal government. The creation of a multiclan army will take decades, time that Somalia does not have.
You can either be practical and go for the clan militia solution which is the proven route, or be ideological and try to create a "rainbow coalition" that will probably melt away at the first encounter. Any army you build in Somalia will of course be a Somali army, we are arguing as to how it should be structured.
If we fail to integrate the SNA there won’t be at all true peace in Somalia. It’ll be more like early 2000’s if anything if we go down this path with people putting their tribe over country leading to countless of skirmishes.
A multi-clan approach is the only way forward to a stable Somalia. Better to go through growing pains as a coalition than to see the same people battling over resources in the next century