Honestly, I'm not sure if this is a viable RPG and I've played pretty much every game in the series. The story isn't about individual soldiers on the battlefield as it is about Kane and the various leaders of Nod and GDI that have come and gone over the years. Individuals with very human flaws but also leaders of men handling the burden of command in various ways. Most RPGs I've played aren't set up to play that sort of thing.
Perhaps if the traditional attributes were swapped for things like "Tactics" and "Research" and players were a body of commanders working on different tasks in the same theater, it might work.