cbwjm
Seb-wejem
Someone to deal with traps and locks, which I guess is anyone who gains access to thieves tools via class, background or feats. If picking a specific class though, I'd say either artificer or rogue for their skills with thieves tools. Rogue can also have decent stealth if you also want a scout and can hit hard with sneak attack. The artificer can get some good support abilities, adding a bit more magic to the group as well as enhancing people with infusions.