Interesting team comp idea

Yes, they're good vs assassin enemies and pretty fun to use. Also if you like them, just roll for them.
I've done similar things like that, Tamamo + Helena + Medea, NP spam is real.

Get rekt MVP support freaking Art Crit party :
Hans + Mozart + Waver, Hans use his NP and Crit dmg up to buff Waver, then the next turn after i got full Waver cards, Mozart use party Art effectiveness up and 50 Crit stars.
It's really effective vs Assassin enemies lol.

Just one of the most silly things i've ever done 😂
I'm one of the guys who will roll for favorites, funny or even meme servants.

Fun facts :
- Queen of Sheba NP power is over 9000, as you can see she is a master of Naruto Giant Rasengan, Frieza's death ball and a sun fragment from Gawain sword Excalibur Gallatine.
- Nero Caster is a Gundam Saber, she shoots laser beam using a Giant Gundam theater.
Technically, she's almost class-less with her skill.
No matter what her class is, she's a saber. She don't even have any freaking wand !

It is good if you say you want to have this team as Waifu team (typically supporting Nero), but it has severe issue related to durability. So in gameplay it worked in amusing fight or relaxing fight, or meme, but not tough boss fight. Also quite rely on RNG for having a good cards in order to Nero's NP spam.

Sheba and summer Nero have amazing NP gain which is probably the top-class of all servants with >2 Art cards. But honestly I prefer caster team with more Art cards (even Art NP), in most cased fighting Assassins required team-wide synergistic effect because of poor Caster's 0.9 multi-filer and limited servants with star-utilizing (only Alice, Sheba dont have star absortion).

If not considering Sheba's NP is ST, Helena is more suitable. Or change Tamamo to Caster Gil because it is hard to do her NP spam anyway. Put star generator CE to Helena and Tamamo/Gil, put star absorption CE to Nero.