In sheer dead, maybe. As a percentage of the respective total forces, much less so. Lee squandered more than he could afford. And contrary to Grant at Cold Harbor, who (thanks to lousy recon by Meade) didn't know how dug in the CS forces were, Lee could see perfectly what the Union postion on top of Cemetery Ridge was.
Now I will cut Lee some slack, too. If we believe that Stuart was supposed to hit the Union rear at the same time, the attack might have gone down as one of the most brilliant of the war, and it might have even won the war for the south.
Then you end up in the position of elevating Custer into the man who singlehandedly saved the Union.
You also have to remember that Lee felt that the Federals were weakest at the center. There were more units in reserve than he realized, until the attack began. Under the tactics of the day, the charge was a sound plan, but as you mentioned, Stuart didn't do his job, and also the execution, (Longstreet's bad) was not carried off correctly.