Spencer Rattler’s first start was…

Carr can do roll-outs with single and two-stacked reads. He's done many this season. I'm not sure why you guys are suggesting he can't.

Rattler wasn't out there scrambling like crazy and making guys miss. He had a few good scrambles up the middle for relatively short gains, but I did not see a guy who is going to win games with his athleticism. He's going to need to develop into a passer who can take advantage of his big arm.
Rattle reminds me of Winston a lot more than he reminds me of Mahommes. He's got the same strengths and weaknesses that Winston has.

On the plus side, he's got a strong arm, can occasionally make an incredible throw, and can occasionally scramble for a good run. On the negative side, his ball placement accuracy is inconsistent, he doesn't see open receivers right in front of him or he ignores them to make a riskier throw, holds onto the ball too long waiting to make a big play, and has at least as many bad scrambles as good ones while being a little too quick to scramble at times.

All of that could improve or get worse. Only time will tell. An NFL QB needs a lot more than a strong arm, confident "body langauge," and the "it" factor to be successful. A lot of strong armed, poised and confident QB's have been unsuccessful in the NFL.