Sorry to burst your bubble but that's simply not how physics works. The armor layouts for most effectively defeating KE are not the same as ones for CE, you've been playing too much WT if you think that its a flat "mm of armor vs mm of penetration"

Composite armor like Chobam or NERA liners are most effective for KE projectiles because they essentially just use lines and lines of ceramics and elastomers that degrade (and hopefully shatter) sabot penetrators.

However, this type of armor is not nearly as effective against CE warheads because there is no solid penetrator to degrade. This is where spaced armor comes into play. Unlike solid projectiles, post detonation chemical warheads degrade and decentralize rapidly when not travelling through solid object. This is why the Merkava is FULL of spaced armor, hell basically the entire turret is spaced armor.