No, we have no idea why the Centurion's name is Horace, it just sounded funny. Obviously both the Dark Trooper and (to a lesser extent) Oblivia have been sized up - the original size difference between the trooper and the Cylon made it look like he was way too young.
For those keeping track, a Number Three would be Lucy Lawless. Who wouldn't be tempted to stray!
Caption: Still secretly ashamed of his own infidelity many years ago with a Number Three, DT-97's father clung to his outmoded prejudices.
Horace: No son of mine is dating a skanky, cheap, good-for-nothing... organic!
Mrs. Horace: Horace, please...
DT-97: Format you! I love her, and we're going to the Federation where we can get married!