Fair enough I written this quickly and did not re read it after I posted it, your right Titan cpus are not 1080's
but in case for clarification.
When they produce the GP104, (1080 and 1070 Video cards GPU Chip ) the middle of the wafer is still the best video chips (and end up in classififcations before being sold to resalellers to build their video cards on, EVGA buys the best cpu they can and make their FTW series with them.Meaning if you bough a FTW and a standfard SSC 1080 from EVGA, you will find overclocking a FTW easy and get more speed out of it than a plain SSC card, which has a lower quality chip on the video card. this applies to all video cards on the markets EVGA, MSI, Gigabytes etc. and if you look at numerous revierws on the subject for years. performance ect , find quite often gigabyte Asus etc at the bottom of quality when you take in consideration their abilities to overclock their cards. MSI EVGA etc tend to count on these factors to sell their products. and not over charge for a good quality solid product.
of course this my personal opinion, based on 30 years in the industry.