Used beginner promo codes, kael to six star first, he gets benched too early?

Starter Promo code gives:

• Elenalirl - Poison, poison exploder
• Fayne - Poison, Clanboss champ
• Bellower - void champ, Aoe attacks, Campaign farmer
• Tagoar - reviver, speed buff
• Tunahanarak - Speed buff, dec attack, inc dec, dec speed, conti heals

We get Artifacts from beginner passes, Bellower is farming 12-3 brutal.

Does kael still need to six star at first?
In my opinion, he gets benched early from Clanboss, Dungeon.

Campaign farmer - bellower

Poison - fayne, elenaril has it covered, EVEN Frozen banshee is way better than kael

Kael still could be used for FW.