Most sites had Martin listed in round 4 this time last year. It wasn't until February at the combine or senior bowl (or maybe late January) that some NFL analyst (Mike Mayock?) basically broke the news that Martin was getting 1st round hype in NFL circles and everyone quickly fell in line.
Tannehill was assumed to have badly hurt his draft stock after a tough senior season. You did a great job being ahead of the curve on that one when you found an obscure article which showed that scouts still found him to be a top 15 talent. Most people assumed Tannehill would go 2nd round- maybe late 1st. When he went 8th overall, people laughed. They shouldn't have. He was rated very high by a lot of front offices. If he had lasted to #12, he might be a Seahawk right now.
I am surprised that Klein wasn't invited to the senior bowl. You compare him to Tim Tebow, and I get why, but Tebow was not fixable. I think Klein probably is. Again, I'm not a fan of his really, but I wasn't a fan of Osweiler either, and I thought Osweiler had obvious NFL potential if things broke right. That's how I feel about Klein too. If some team gets him to step into his throws and gives him the same kind of read option offense that Carroll/Harbaugh/Shanahan have used to help their mobile QBs, I could see him being a legitimate prospect.
You are probably right though. Groupthink can be devastating. Klein could go undrafted because evaluators never learn to dig a little deeper, and very few coaches possess the kind of imagination that Carroll has at QB. They always assume that guys like Brady or Wilson are just flukes and continue on their business. Not that I think Klein is anywhere near that good, I'm just puzzled that he is being thrown out of consideration for so little. I wouldn't draft him personally because there are many other QBs I like much more, but I like him a lot more than a lot of guys that have been drafted the last few years (Lindley, Skelton, Dan Lefevour etc).