What's the best set up for these servants?

For what purpose? Farming or Boss Killing?
Ideally
Farming: AoE servants plus any support. Make sure you have NP Charging CE like Kscope, Dragon Meridian, Imaginary Element. Salter, Lancelot, Mordred, Elizabeth, Emiya are suited for this
Boss Killing: ST Servants will be your main servant plus support like Hans or the obvious Waver, plus an AoE to sweep trash mobs and a taunter if you feel need it. Shiki is good here, and some of *3 are also amazing like Ushi, Caesar, Cu.

Basically you should combine characters with similar decks and np color. There's a couple exceptions with support servants but for now it should be the best option.
For an example: Mordred has 2 busters and buster-np with a skill to power-up her buster attacks, so you better get her other buster-orientated teammates for buster chains in order to deal more damage (like Elizabeth Barthory or Lancelot).
Another example: look at Shiki. She has 2 arts cards and arts-np with a skill to power-up arts carts, so her teammates should be also arts-orientated (Medea, Hans) in order to spam arts chains, and by that, their NP's.
It's not necessary, but improves team performance. But some characters has unfortunate of having different card deck and NP color. Emiya has 3 arts cards, arts buff and buster-np, Carmilia has 3 quick cards and buster-np and so on. It's not like they bad because of it, but it makes harder to fit them in some team.
Anyway for the beginning it's shouldn't be a problem to clear first 3-4 chapters with random characters, and for cleaning daily quests: take as support 90lvl Caster Zhuge Liang - he's 2nd and 3rd skills charges every teammate 10% of np bar each and 1st skill charges 30% to a selected servant - so you should take 2 servants with AoE NP and equip them CE that charges np bar at the start of a battle. Clear first wave with normal attacks and just use 2 NP on the next two stages.

Lancelot, Saber Alter, Mordred and Liz should be in a farming team, you don't use them for boss killing or hard contents, they are farming servants, give them CEs like Kaleidoscope or Imaginary Element, bring them when you farm hands or doors, then you are gucci. Though Salter can work in a boss killing team, but she won't be as good as the true dedicated boss killer saber, like say, Okita, Caesar and Rama.

Shiki, Emiya, Carmilla, all three of them are heavy NP spammers, so, place them in an NP spam team. One of them with 2 art support will work wonder.

Andersen + Shiki/Emiya/Carmilla + Mozart, go with this setup. Emiya desperately needs Andersen's 3rd skill to work well, as without crit stars, honestly, he sucks. Andersen's 1st skill will further boosts your party's critical damage, this works amazingly perfect with Emiya also. His 2nd skill is basically NP on demand skill, while his NP is, honestly not that great with that missable buff, but his hp regen grants you a lot more hp than any dedicated healers will. Mozart is there for his 1st skill, party wide art up buff, almost as strong as Tamamo's but it's party wide, and lasts 1 turn, so, time it right. His 3rd skill isn't available right now, but when it's actually unlocked, that's 50 free critical stars for your team, guaranteed crits. Both Mozart and Andersen has 3 art cards, meaning they can help you keep the art chains going, giving you easier time to spam NP.

I'm assuming you don't have both Tamamo and Waver, so, I won't mention them here, but if you surprisingly have them or you have friends who placed them as their support, then by all means use them alongside your servants.

Also, believe it or not, this is a setup for hard contents.