Saberlot va Nero: who depends on arts team more?

They have so far difference in gameplay. She's Backliner anchor but still both is art type.
Both can be Boss killer, one of with huge damage and one with immortality.
Roll for him if you don't have any decent ST saber i have pretty similiar situation like you, but i raise Caesar and Bedivere because i'm F2P and he's so hard to get so it's better than nothing.
Also Nero have better Farm ability and daily usage than Saberlot.

You can ignore Class advantage if you use Papalot because he's too damn strong with Art Crit team.
Saberlot is Great choice to pick so why not? Don't overworking Nero every day LOL.

Saberlot for sure imo. Nero’s a survival-based servant, so by nature she isn’t as reliant on support.

I got saberlot with a ticket and I already have nero np2, and who I wanted was Ozy or Artoria Lancer....

Well Saber Lancelot has only one job but that job he is S+rank is damaging. In fact, there are pretty rare servants have such great combo of star generation (Say NO to Quick Card) + Star adsorption + Critical-up (and even instant NP charge).
Teamed with 4060 Tamamo (Art-up+Healing+Skill cooldown)/Waver-Hans (Defense up+Attack/Critical up) or even Helena-Marie (Brave chain or additional stars constant generated, etc) make saberlot somehow better than Okita's damaging team as top of Saber's team. Then Saberlot can even kill any non-lancer/berserker boss as a piece of cake and do NP spam (NP effect also great to non-class-advantaged enemy)

It is not wise to compare Nero OG to Saberlot as damaging. Umu is more focusing on durable fight (maybe S rank for durability, same as snowcastle CE Herc), and quite less dependent to team. Indeed, Tamamo/Waver etc can also boost Nero's performance, but comparative speaking, it is still not a necessary. Since:
Generally a (not-tanky) Art team's DPS has either ability to slash enemy boss in few rounds (Saberlot, Archuria, Li Shuwen, etc), or has decent supportive skills/NP to the Art support servants and achieve win-win effect (umu Bride), or strong debuff like reduce enemy charge, etc (Orion, Vlad).

Nero OG has nothing related to them. If you put her in team with Tamamo/Waver/Hans etc, you may find that the enemy can crush your Art support easily because of her mediocre damage/NP (and class for star adsorption) will not kill the enemy boss at same speed as Saberlot, and no supportive skill for your supports (like Bride, 1st skill help Tamamo to spam NP, and 3rd skill help Waver/Hans to stand longer, and even NP can reduce Critical chance of enemy boss to prevent a sudden attack), and even not like Vlad/Orion then just wait enemy to release the NP and Nero can do nothing help. Off course the good thing is that Nero OG wont rely on Art support then it is even not necessary to build a team for her.

when I play Nero OG I always do (1) put her as final back-line versus Lancer boss (2) Farming and facing Multi-classes enemy like small boss of Lancer. (3) tanky team with Jeanne/Mashu/Tamamo.... then Nero OG can provide more-or-less damage to lancers/berserkers and (4) dual Nero. I even consider there was no "Art support" for Nero OG, but multi-functioned support like Jeanne (AOE NP enemy)/Mashu (ST NP enemy)+Tamamo to make Nero OG provide constant damage in a Marathon match, no huge critical damage as Saberlot. It is still a Art-team somehow, for Art-chain purpose mainly.