BY DAVID THORPE

Art by Mike McGrath, Jr. Instagram: @michaelmcgrathjr Twitter: @mikemcgrath

We’d been saying it for a while: When Joel Embiid was off the court, the Sixers just weren’t the same. That can’t be said now. When Philadelphia and free agent Al Horford agreed to a four-year, $109 million deal Sunday night, it made one thing crystal-clear: No one…