Double Wards still worth it, but more so for 5* level than 4*. Don't bother at 4* level.
Personally, I'm doing the following for 5*
Elemental booster: Empower element + 2 xL15 Empower Element inherited (e.g. King Behemoth with 2 xL15 Empower Lightning inherited)
Elemental Dampen: L10 Dampen + L10 Dampen inherited. (e.g. Famfrit + L10 Fire Dampen inherited). The second passive varies, but going forward, HP Boon is probably the safest choice.
General Defensive magicite: Phoenix with L8 Blade Ward / L8 Spell Ward inherited. Can also use Famfrit or Mateus if you want.
Attack Booster: Currently Manticore with 2 x L15 ATK Boon inherited. Those will change to L20 ATK Boon as soon as I'm able to. I will probably transfer those 2 xL20 ATK Boons to Madeen later.
Magic Booster: Currently Quetzacoatl with 2 x L15 MAG Boon inherited. Those will change to L20 MAg Boon as soon as I'm able to. I will probably transfer those L20 MAG Boons to Madeen later.
Critical DMG Booster for Cloud: Belias with L10 Deadly Strikes inherited. Only Cloud (and later Sephiroth) uses this. Will probably transfer the 2 xL10 Deadly Strikes to Madeen later.
Healing boost magicite: Currently this is just Siren with an otherwise useless L15 Empower Holy inherited. Basically, MND Boon + Healing Boon turns out to be very useful in some fights - I had massive problems clearing Mateus with Elarra USB as solo healing, but once I dropped Siren in my deck it was manageable, simply because her entry now healed 7700 instead of 5400, meaning that I didn't automatically die to 6000 AoEs in Phase 3. I'll probably replace Siren with Lakshmi later on.
BTW, while they'l be replaced later on, I have two Evraes right now that I use, one with L8 Fast Act and the other with L8 HP Boon. The latter is used far more frequently than the former.
The idea behind these is to be as versatile as possible, not necessarily have a deck optimized for the next magicite in a wheel. If I need, say, physical Lighting and Fire physical damage, I can run Behemoth King, Belias, and Manticore, and still have room for two defensive magicites. If I need to defend against Fire and Ice, I can drop in Phoenix and Famfrit, and still have room for offense.
The only places where this becomes somewhat iffy are for Holy (Madeens will be around for other stuff, so I might not need a Madeen with triple Holy empower), and Wind (Typhon and Syldra have ATK+20 and MAG +20 natively, lessening the need to bring a dedicated ATK/MAG booster).