I'd actually recommend LX F. DXB-FRA is a long 6-7 hour flight and having a first class suite vs. a 2-2-2 J config is pretty nice. Plus, if they deny lounge access at ZRH, at least you'll get the Senator lounge, which is pretty fantastic by itself.
The only big downside is the extra hop from ORD-IAH. I hate flying through ORD, especially in the wintertime. If your DXB-FRA is night time, then I might just go for LH F so you can sleep on LH J and then get a direct flight to IAH.