party of 5 wood elf assassins.
Alpha strike or bust.
Wood elf gives more oportunity to hide, +5 ft extra movement(when surprise fails it's extra 15ft with double dash for running away), longbow for extra damage and larger range of alpha strike.
Elven accuracy and alert must have feats for all.
One of them should have the sage background, party needs a loremaster
I'd give at least one of them a decent WIS and the Observant Feat. That is a great feat, almost broken. I'd also give at least one, more if you can spare the feats, the Healer Feat. Not a ton of healing, but a decent amount and can do it once per short rest for each party member. Sometimes it comes down to a player just needing to take one more hit, but even then can be stabilized with 1hp and back in action shortly after things get under control.
party of 5 wood elf assassins.
Alpha strike or bust.
Wood elf gives more oportunity to hide, +5 ft extra movement(when surprise fails it's extra 15ft with double dash for running away), longbow for extra damage and larger range of alpha strike.
Elven accuracy and alert must have feats for all.
I'm going to suggest something a little outside the box, may not work for your vision but I think it might be fun from both a game play and RP point of view.
What you seem to be missing is muscle. A front line tank. Somebody with a good athletics score. Yes, the swashbuckler is front line but they're the hit and run front line. You need a guy that can block the way for a round or two.
So there are a couple of ways of doing this. The goal is someone with a lot of HP so I'd add the Tough feat.
Go against the grain and have a strength based rogue, maybe a mountain dwarf for medium armor and the strength and con bonus. If that doesn't appeal, Moderately Armored feat would give someone medium armor and a shield. A dragonborn thug could fill this role nicely with their bonus to strength and charisma.
In my experience stealth is great, but most monsters have a pretty low passive perception so limiting yourself to 14 dex isn't the end of the world and there's magic that can help if needed.
party of 5 wood elf assassins.
Alpha strike or bust.
Wood elf gives more oportunity to hide, +5 ft extra movement(when surprise fails it's extra 15ft with double dash for running away), longbow for extra damage and larger range of alpha strike.
Elven accuracy and alert must have feats for all.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.