modifier levels and crafting / tier levels

Lets take as example an amulet. For a Warrior, the perfect amulet would be: (imo)

#Life
%Life
%Armor
Melee skills
Str
Attributes

Now the melee skills and % life are both the most important mods and the rarest mods, so you would want them first before you start investing heavily in crafting the rest of the item.

They have however only 3 levels. Does that mean that if you find T4-5 rings, these mods can never be on them ?

Does it mean you basically cant use omen of whittling on an item with these mods because the most important mods will always be the first to go ?

I understand it is not meant to be easy to craft the perfect item, but if above assumptions are correct, i think its a bit extreme. It would mean you must roll these 2 mods last. The chance to roll life is 0.6% per mod level, the chance to roll 2 or 3 melee skills is 0.5% combined. If you were to try whittling until you get either of these mods, more than 90% chance, you're first gonna find another mod that matches the level of the existing mods, so the whittling stops targetting the correct mod. Hance the chances of crafting the perfect item are about:
0.6% * 0.5% * 10% * 10% = or roughly 1 in 3 million. With whittling costing 10divs, that means 30 million divines average.
I hope im totally wrong....