Klose was poor in 2004, IIRC that was before his evolution as a playmaker, back when he was a pretty run-of-the-mill targetman. While Schneider had already lost a few steps by then. Ballack & Lahm I'd include as starters, but not the other two...and that only so Kimmich could play in the midfield behind Ballack & Goretzka; as current Kimmich > a 20yo Lahm.
I have a tough time making an all-time team because I really struggle with nostalgia too. I was raised on tapes of Netzer, Beckenbauer & Gerd, but I also have to acknowledge that if you took a time machine to put Netzer in the modern game, he'd be a poor man's Kroos unless you also had him growing up with modern training & nutrition...at which point he's a completely different player.
So it's really hard for me to do an all-time team; guys like Gerd, Beckenbauer & Rummenigge have to make the team...but in an objective sense, what they could do on the pitch today would not equate to what they did then. That's why it's hard for me to argue against guys like Neuer, Hummels, Kimmich, Müller, Gundogan, & Kroos. making an all-time 23...ditto the recently retired Lahm, Klose, Özil & Schweinsteiger.
With more recent all-timers like Sammer, it's easier; pre-kneesplosion-Sammer is in no matter what. But when we get back to the Breitnenigge generation and before them, I don't know what to do...do I pick based on how they did against their peers or how they would do if collected at their peaks with a time machine to be put on a pitch together?
TL;DR: depends on the methodology we're using to pick this all-time team & whether we're doing an all-time 11 or 23, but Neuer, Hummels, Kimmich, Müller, Kroos & Gundogan all have their arguments.