Kidd is just as strong as Apoo and Basil and Drake which is unconfirmed. Kidd obviously doesn't have great control over his DF ability as of Sabaody or else he could have just pulled the pacifista's apart.
Also pretty sure Law's room means he doesn't need his sword but it helps when he has it and Zoro can still fight just as well without a metal sword, we know he has haki so if he went at Kidd with 3 Haki imbued sticks(like vergo) and used Oni Giri that would be the end of it.
As plenty of said Kidd may be able to do wider damage(debatable) than Luffy but Luffy is the worst opponent style for Kidd, him and Apoo both have an instant advantage in the battle as I'm sure Kidd is used to disarming his opponents.
Kidd and his crew have the potential to be big players in the manga and I assume they will, they're just too nice of a crew to throw away but as of Sabaody(since that's the last time we've seen anything from all 3) Kidd is below them and until we see what he learned in the TS it's probably the same.