I'm pretty good on Archer, especially Saber, Rider, Assassin, Caster, Avenger, and Ruler. Lancer and Berserker need better units.
I do have Alter LArturia but she is for farming more than challenge and not ST NP. I don't really have a good ST Lancer atm but Shisou would be great if not Karna. Though I'll more than likely just use Raikou Lancer instead lol.
For Berserker still waiting on my Raikou to complement my Herc ST NP. Don't really like much else in that class for servants.
I would like a ST Archer of the higher rarity but tbh I have so many AOE versions and Robin Hood gets insane work done as a 3* Archer. Oh I do have Orion though lol. Just remembered as I was looking over the tier list. So Archer class is pretty set.
Saber class is way too crowded for me. Nero Bride gave me a ST NP saber but I do want Musashi since I like Buster more. I have Mordred and Salter for AOE spam.
Rider I just have Ozy who can put in the work for ST damage. AOE I have Medusa but Martha will replace her if need be later on once I level her up.
Assassin I have Jack for ST and Carmilla as well so I'm fairly set. Don't have AOE assassin but who does? I wouldn't complain if Cleopatra ended up in my Chaldea though. But she is a want, not a need servant atm.
Caster I have Merlin, who the hell else do you need? Also have Caster Gil and Nursery Rhyme. I do want Xunzang really bad but she is after Raikou.
Avenger I have Gorgon and Lobo. Nothing crazy but I love Gorgon and she does hella AOE with Merlin buff. I do want Jalter eventually but no rush for her.
Ruler I have Shirou Amakusa so no issue there for AOE.
I'm basically almost done collecting the servants I really wanted. Now I just need to save up to get the servants I want once the servants I need have joined me.