i would bet not. i've got big ornates and little dels and little endli and big dels. no one bothers anyone except the BGK that doesn't like the little senegal stealing her hiding place.. lol.
I too have Sens with large Ornates and zero issues. As long as the Sen is not the size of a nightcrawler of course, I see no issues. Ropefish.....different story. Made that mistake.
I think you'd be fine honestly... a full grown sen is like what, 14'' and plump? Ornates grow pretty slow too. Think you'd be ok as long as you don't have a massive ornate and 3'' sen! Haha! Good luck!
I think it could be possible that the ornate could eat them if he were to grow much larger or is just very hungry. Someone posted a picture of a 10'' ornate with a 8'' sen in its mouth. Both were dead or course cause the ornate basically chocked. Not sure whos picture it was. I got that response when i asked the same thing your asking a few months back. But i have been able to keep both types together fine, the only problem i noticed is the ornate biting at there tail fins but he never tried to actually eat them.