Lancelot vs Okita, Musashi and Nero Bride

I feel like my np2 lvl 90 Lancelot always outperforms my nero bride. Okita might be fun to have with Lancelot to feed him extra stars to crit with, but probably not necessary unless waifu.

All the servants you have listed have different uses.
Lancelot is a self sufficient arts-crit damage dealer who focuses on dealing a large number of art-crits to fill his NP which further increases the potency of his arts cards.
Okita is a self sufficient quick-based NP spammer with high NP gain due to her quick-crits and high NP and Star gen stats causing her to fill large amounts of NP with each quick/art card.
Nero Bride works as a pseudo support / secondary attacker with 3 powerful targetable buff skills and a BBAAQ Deck allowing her to use her arts NP quite frequently. Unfortunately, Nero Bride's skills don't synergize with herself very much leaving her as a mostly support unit and back-up damage dealer if necessary.
Musashi is a buster-based servant who focuses on her 1st skill which doubles her hit count. This skill, plus her own high NP gen stat, allows a single arts crit at the end of an NPBA-chain to fill her bar back up to 100%. Unfortunately, this may be hard to do due to her BBBAQ-deck. She focuses on this skill so much that she becomes near one-dimensional as a servant without it.

In conclusion, the best among these 4 is entirely subjective to what support servants you have access to. Objectively, Musashi is the best due to the existence of Merlin while Tamamo has yet to get her 3rd buff and Skadi having yet to be released in NA. Roll for either character preference or to compliment the servants you already have; if you only have Tamamo, go for Nero and if you have Merlin, go for Musashi. In the end, it relies upon what you yourself want, any of the 3 are amazing roles, even if you have to use a support servant from your friends list in order to properly use them.

I feel your pain, man. But since Musashi didn't come home, I would highly recommend rolling for Okita. In the absence of Merlin, she is (in my opinion) hands down the best ST Saber.

They are different. Lancelot is an offensive arts saber. Nero is a support/offense hybrid arts saber, and okita is quick and Musashi is buster. If there are other holes in your lineup I'd suggest filling those first, but if you like them by all means go for it.

If all you need is a ST Saber, Saber Lancelot is more than enough to replace any 5 star ST saber and able to replace their role in most situation. Lets be honest, FGO is an easy and simple game and unless for waifu, saberlot is more than enough. Would recommend you to save your quartz for other banner for other servant you lack.

Yes it is good to pull other Saber if you already maxed Saberlot ( max skill + Bond + Grailed ) and need Musashi to cover that ST role.
I've some max bonded saber, so i use another one to cover that role.

And also if she's one of your favorite saber then go for her.

For me, Saberlot alone is enough to rekt things so hard ( his crit is pretty consistent and technically he just ignore class advantage system ).

musashi is best saber ever no doubt. she's skills,deck and np perfectly fit on her. And make her perfect for grand battles.