You sort of miss the point. Both points.
Steals are one thing, blocks are another. The kind of blocks that 6'5" guys get playing against college opponents won't be so plentiful in the NBA. He will get some blocks at the next level, but it will be a relatively insignificant part of his game. I pointed out that you eliminated the big men because Thybulle isn't a big man. Which is EXACTLY the reason he won't be getting big numbers of blocks at the next level. (I know, I know... Dwayne Wade got a lot of blocks. If Thybulle gets as many, I'll come back and admit I was wrong.)
Danny Green has been an outstanding defender. He has also been a VERY good 3P shooter. That's one more plus than Thybulle has at this point. And you still can't deny that Danny's inability to drive with the ball has been seen as a big negative. If the Spurs bring in a guy who defends like Danny (or even better than Danny), but can't drive to the basket OR shoot the 3? PATFO may still love him, but I guarantee you this place won't.
What the ... let's talk about steals. Danny has averaged about 75 steals per season. He's only had one season with 100 steals. The list of guys 6'5" or less who have had 110 steals or more in a season is dominated by Chris Paul, James Harden, Dwayne Wade, Russell Westbrook, Steph Curry, and John Wall. How much attention would any of those guys get, if they had next to no offensive game?