By now, most internet-dwelling Westworld fans have come across the theory that the story is operating on at least two different timelines, and William is actually the Man in Black from 30 years ago. But some key clues from Episode 6 open up a whole new world of speculation. For example, is Teddy really William on Westworld? Combining what viewers know about hosts being created from human models with the possibility that the show is running on separate timelines, it's totally a possibility.
Early on in the series, the parallels between White Hat William and Teddy were almost too obvious to ignore, particularly in regards to Dolores. Fans watched as Teddy picked up her dropped milk-can on several different occasions, an ever-repeating little interlude that was part of Dolores' "modest little loop." Then, when William arrived, it was he who picked up the dropped milk-can, and the hapless Teddy was nowhere to be seen. The moment is symbolic of both characters' white knight sensibilities, and it's important to note that there's still never been any interaction between William and Teddy. And remember when Teddy said he'd rather earn a woman's affection? It sounded awfully similar to what William later said to Clementine. Could it be that William fell in love with Dolores and his desire to save her is what inspired the engineers and writers to create Teddy?
Viewers already know that there is precedent for creating robot versions of real people. According to Dr. Ford, his partner Arnold recreated Ford's entire family, allowing Ford to relive interminably his happiest memory from childhood. Ford keeps the little robot-Fords in a little cabin in a secluded area of the park where he can visit them and spend time with them whenever he likes. Accepting for the moment the theory that Westworld is showing us two different points in time, perhaps the engineers saw the connection between William and Dolores and created a robot version of that character to keep Dolores on the homestead and committed to her quiet little traumatic storyline.
This supposition also encourages some other possibilities, including the popular theory that Bernard is actually an android version of the mysterious Arnold. This would explain why both characters have lives "marked by tragedy," and why Bernard is so fascinated with the hosts' consciousness, as Arnold was.
Other than the character parallels, there isn't a whole lot to support the theory that Teddy and William are the same person, or at least, that Teddy is based on William. However Westworld is so tantalizingly vague with its clues that it is undoubtedly possible and opens up yet another wide range of possibilities to the show's ever-changing storylines.