No he's not. Zeke's on pace for 352 carries. He's on pace for another 32 receptions, so maybe you meant touches. But the research on RBs indicates that receptions aren't that big a deal: it's the rushing attempts that wear them out and wear them down. Still, 352 carries is a lot for anyone.
The rookie wall is a real thing. Will they hit it? None of us knows, even (especially?) those talking like they do.
Of course, the likelihood that Zeke'll get to take game 16 off should help.
As far as Dak, I know I'm alone on this, but I love the idea of having Romo start vs. Baltimore (if he really is ready) and Dak on Thanksgiving. We get to see where Romo is in a non-conference game, and Dak plays on (more than) full rest against the 'Skins on Turkey Day.