Obviously, we need the current top tiers to move up that high, with things being spaced out accordingly. Until the various “eras” capability-wise are spaced enough apart to where they only match amongst themselves, high tiers will never even begin to be “fun,” much less “balanced.”
Starter MBTs at 7.7-8.0 are far too good to ever be seeing the swan-song of heavy tanks (Caernarvon, T32, T32E1, Maus, E-100, IS-3, IS-4M, IS-6, T-10A, Somua SM, etc).
The M103, Conqueror, AMX-50 Surbaisse, AMX-50 Surblinde, and AMX-50 Foch belong alongside the starter MBTs. Especially since they all use the same gun, and if they all received each other’s respective rounds. The M103 did test-fire T102 APDS, which penned even more than the Conqueror’s (495mm at 1000 yards at 30 deg from vertical). The likes of M48s, Leopards, AMX-30s, T-54s, M60 base models, OF-40s, etc all belong here. As would the IS-7 and T-10M.
All the stabilized early MBTs plus the 279 belong in a separate tier well away from everything below it. All IFVs and nearly all HEAT-spewing go-karts belong here as well. Almost nothing here should have both stabilizers and thermals, however, as thermals are basically a wallhack against anything without them. Yes, every last BMP, Bradley, Warrior, Type 87, 906, etc all should be here. These things INFEST starter MBT tier.
A further group above begins the era of stabilized advanced MBTs with thermals, starting with the likes of the Leo 1A5, premium Leo 1A6 L/44, so on and so forth.
In each of these groups, they would be all 1.3 BRs apart so they only match amongst themselves, and can neither be uptiered nor downtiered. The tech gaps between them are just too immense for such a system to work without upending damn near everything about the gameplay.