Alston never caught a pass anywhere from any college QB, so your prediction that he'd be great at Wyoming is bold...entirely unfounded, but bold.
It's clear you don't think Johnson going to Wyoming hurt NU. That's fine. I hope it's also clear, especially after watching what's happened on offense the last six seasons, why having a guy who averaged 17.7 YPC with a QB who averaged 6.7 YPA would be a huge addition to any Nebraska team.
As for Lee, he had no D1 offers out of high school. Kudos to the kid for going JUCO and getting his shot, but NU took one DE in 2017, 4* Guy Thomas, and then four more in 2019 when Lee was leaving IWCC. Each one of those players is still on the team. Perhaps most importantly, Lee isn't a difference maker for Kansas, so it doesn't make sense to bemoan him not being a difference maker at Nebraska instead.
That aside, Ben Brahmer looks like a solid prospect.