User blog comment:PurpleWii/What if more items were like Sterak's Gage?/@comment-26378838-20160418131253/@comment-1330314-20160418134625

Many mana champions received changes to their mana regen at around the same time the stat was reworked, and I think the same could work for other stat conversions. Since you have a clear target roster of champions who will want to build certain stats, i.e. tanky champions for health and resists, AD champions for AD, etc., you could adjust the bases of those champions to meet certain target values (e.g. "Alistar should get ~800 health from Warmog's at level 18, and ~100 health from a Ruby Crystal at level 5, so he should have something like 15 more health growth). I would not recommend picking level 1 values and draw a hard equivalence between current stat values, since that would be a straight buff to all items, plus items like Ruby Crystal generally don't get picked until a few levels later. I also don't think it's all that awful if health ends up being weaker on items early on, since it's such a generally good stat that picking it just for its versatility would still be worth it.

As for cases like Thresh not making good use of armor, one option could be to make his souls increase his base armor, and another could be to give him a certain amount of armor growth so that his average-case for base armor + items + souls would match his current values. The same could go for, who has terrible health growth to "compensate" for his W passive.