Luchs 7.7 > 8.0
This is senseless and not thought out at all, but someone else already described why so I won’t say more than that.
Df105 8.0 > 8.3
I don’t see the justification for this. It’s unstabilised, only fires HEAT (which isn’t bad, but personally I prefer APDS, and it certainly isn’t the best option), is paper (light tank, admittedly), and isn’t really that much faster than the other fast-tanks around that BR, and lacks a lot of the technology that many 8.3s have. Its sole advantage is the 5.0s autoloader, which is good, but not all that game-breaking, so to speak.
Gepard 8.3 > 8.7
While the Gepard is good, it isn’t the fastest, and has an extremely large profile. It is also a bit worse than the various Gepard clones (though not worse enough that I’d have it lower than most of them). The problem with moving the Gepard and its clones up is that this is one of the few BRs where AA actually feels potent against CAS, and since its anti-tank performance isn’t too dominant (that is to say, again, good but not outright OP) I’d prefer to avoid setting a trend of uptiering AA when they actually reach a state of workability.
Begleitpanzer 57 9.3 > 9.7 or 10.0
This puts it potentially .3 below the PUMA, which I’ve heard many people consider overtiered as is, and puts it in the same region as 2S38 (which is admittedly undertiered, and thus not a perfect reason not to move it up). As is, it’s a full BR above the first Bradley, which seems more reasonable; that is to say, from my perception, it is about 1.0 BR worth better than the first Bradley in capability, and that’s about where it is in BR now.
The Begleitpanzer I am admittedly less certain about, as I’ve only somewhat recently had much experience with it and Germany doesn’t have any usable IFVs before that I can compare its gameplay to, so I’m still getting used to the general IFV gameplay (the Marder is effectively a poor AA gun with a poor single-fire ATGM). If anyone else wants to weigh in more on comparing it to other IFVs that would be good.
I’m only speaking on the German stuff because it’s the main stuff I’ve played and can speak on, especially after the various BR changes over the past year have messed with my memory of a lot of the balancing. This is also why I haven’t discussed the Panther D and proto-Panther, as I don’t know how those BRs currently play.