Composite Armor and Reinforced Armor - Make Leather Useful Again!

Combining Leather Cap, Tunic, Pants, or Boots,
or Chainmail Helmet, Chestplate, Leggings, or Boots,
with Golden/Iron/Diamond Helmet, Chestplate, Leggings, or Boots
would create Composite or Reinforced variations of Golden, Iron, or Diamond Helmets, Chestplates, Leggings, or Boots respectively.

Composite and Reinforced armors would have a durability equal to the Leather or Chainmail piece plus its corresponding Golden/Iron/Diamond piece.

Both Composite and Reinforced armors would add the Leather or Chainmail piece's armor points in TOUGHNESS to the resulting Composite or Reinforced armor piece. Composite would add +7 toughness in a whole set, and Reinforced adds +12 toughness in a whole set.

Diamond Armor (default):
Helmet = 364 Durability
Chestplate = 529 Durability
Leggings = 496 Durability
Boots = 430 Durability
20 Armor + 8 toughness

Composite Diamond Armor:
Helmet = 420 Durability
Chestplate = 610 Durability
Leggings = 572 Durability
Boots = 496 Durability
20 Armor + 15 Toughness

Reinforced Diamond Armor:
Helmet = 530 Durability
Chestplate = 770 Durability
Leggings = 722 Durability
Boots = 626 Durability
20 Armor + 20 toughness

Edit: Netherite acts as a composite to diamond in 1.16, 
Using the smithing table for compositing/reinforcing would be ideal.
This would also give the smithing table a function in the early/mid game, whereas Netherite is a strictly endgame resource.