You know what's strange in your case, I was almost convinced one of the requirements was time in theater at 50 hours and perhaps someother requirement. All the service ribbons you have validates this but, you don't have MEC SF ribbon and you have more than 50 hours time in that theater. So at first I thought well fine, here's a chance to see if we can figure out if there's an additional requirement. For the life of me I can't figure it out, you have almost the same number of wins as MEC SF as you do Navy Seals, and you have more hours as having played MEC SF army than some of the other armies you played and received a ribbon for.
It's can't be best round score because you have a huge BR scorce as MEC SF. I don't get it? Maybe you have to play as MEC SF for each map in theater and you haven't gotten around to doing that yet? I think the first req is 50 hours time in theater but the other req(s), still elude us.