Is my math incorrect or do the marksmen changes just feel unintuitive?

I just did the math to calculate effective health against physical damage with the recent changes to marksmen (increasing health and health per level while decreasing base armor values).

Results: The values for effective health already come online at about lvl 2-3 so actually before any armor penetration/lethality comes online. The increase in effective health goes up to 3-4% at lvl 18 and even with lethality the effective health is higher than before.

In addition to that, their effective health against magical damage is increased even more since their base magic resistance is not reduced at all, not to mention that they now also get MR per level.

I didn't expect that even though the changes are pretty small - but all in all I like that marksmen have their damage potential slightly decreased while their pure defenses are slightly increased.

My calculation formula

EH = (Base Health + Health Per Level * (level - 1)) * (1 + 0,01 * (Base Armor + Armor Per Level * Level)

[I used level - 1 for health but not for armor because of data I found on the champions' leagueoflegends wikia numbers]