Inconsistency with Laser Rangefinder / NVD(Thermals) modification tiers

Why are certain modifications for vehicles at the same BR at different modification tiers?

Laser Rangefinder only:
Rank 2: USSR T-72B3, USSR T-80BVM
Rank 3: USA M1A2 SEP, FRA Leclerc,
Rank 4: SWE Leo 2A6, SWE Strv 122B, GER Leo 2PSO, UK Challenger 2

Rank 2: ISR Merkava 4, ITA Areite AMV, CHN ZTZ99A, JPN Type 10

Rank 2: ISR Merkava 4, UK Challenger 2, USSR T-72B3
Rank 3: ITA Ariete AMV, JPN Type 10, GER Leo 2PSO, CHN ZTZ99A, SWE Leo 2A6, SWE Strv 122B, USSR T-80BVM

Why is this not standardised across all the end-game MBTs?

This should be standard on ALL mbt’s. The strv 122 grind is HORRIBLE due to these inconsistencies.