I think you're diminishing him with thinking his recruiting edge would be all about how famous he is. Sure, his fame is great and all, and it would get him in just about every door in the country (including elite recruits who are considering Texas, Alabama, tOSU, etc), not just in the state of Texas. But, his true recruiting advantages would be much bigger than that.
First, there's the whole NIL thing. There's nobody in all of football who's better at marking himself than Deion. He's as good as it gets at self-promotion, endorsements, etc. He pretty much wrote the book on all that shit. Like it or not, getting to "the league" (hell he played in the NFL and MLB) and having success after that, all of it largely through endorsement deals, will become the name of the game in college football going forward. He would sell the shit outa' that when it comes to recruiting.
Then there's his personality. That dude's energy and confidence are infectious. He may rub some people wrong, but I think on the whole, most people who are around him for even a little bit, find him really hard not to like. Some of his antics in the past may have come off as a bit of a clown show, but as mentioned earlier, I think he knows his audience. He's worked in stiff white corporate America (at least the sports version of it) when he was on air and with various endorsements, so he can undoubtedly turn it off and on when he needs to. Plus he's 54 years old now, so he's probably outgrown some of that. He seems like the kind of guy guy who can own the room regardless of whatever room he's in. He would sell the shit outa' that when it comes to recruiting.
Then there's the parents. Deion is a huge mentoring kids guy and has dedicated a lot of his life to it. He's really big on family and family values. He's had great success after his playing career ended. He's a huge Jesus guy. He's never been in any kind of real trouble off the field that I can remember. A lot of parents would eat that shit up, particularly parents in a large portion of the market he'd be recruiting. He would sell the shit outa' that when it comes to recruiting.
Then there's the DFW market. Deion has chosen to make his life here. He's raised his family here, he's made connections here, he knows high schools here, he's made a ton of local media appearances here, he's done charity work here. He didn't chose to go back to Florida where he's from. Even through all of his TV years, he lived here. Plus he's a Dallas Cowboy (he doesn't identify as a Falcon, a 49er, a Redskin or a Raven) and he doesn't call any of those places home, despite playing at all of them before or after Dallas. And whether you're a fan of the Dallas Cowboys or not, they are the #1 franchise in the WORLD in all of sports when it comes to brand value and marketability. There's a reason damn near every national sports broadcast has a heavy emphasis on the Cowboys and a large portion of the on-air talent are former Cowboys. He and the Jones family still have a great relationship and he'd have unprecedented access, at least to a certain extent, to all of it, including several famous former Cowboy players. He would sell the shit outa' that when it comes to recruiting.
Again, I don't think there's any way in hell this happens, but if you think Deion's recruiting edge at TCU would simply be because he's famous, I think you're selling him incredibly short. He isn't a Gruden (cringe) type situation where people said, "oh all the kids will recognize him because he's on TV so I bet he could recruit." He's got a ton more going for him, especially for TCU, than that.
That said, you're 100% right on the rest of it. Having to actually develop players, scheme, put a great staff together (although by all accounts he's done great at this at JSU), game day coach, etc. are all things that are huge question marks, which is exactly why I don't think there's any way in hell this even comes close to happening. I know we were busting each other's balls earlier, but coaching at TCU is a whole other level than the coaching resume he's got so far.