Arb, Visix/Yumeko, Madame, Magnarr would make a fine team if the first 2 are speed tuned, but that depends on how fast is Arb. 

I'm not a fan of double speed teams in TTA, but I don't see a viable go 2nd in your roster. 

Although on third look I noticed Sandlashed, you could build a team around her for your third team. 

I'm thinking Martyr, Tuhanarak, nuker of choice and Sandlashed at last position to soak up the damage and put AP.

Usually people choose opponents from the power numbers. 

The easy trick is to make 2 great teams and the other the scraps for defense. 

For offense you will need to make them work  but you have really great champs to do so!

Have you got Cardinal somewhere unleveled, OP?

Unfortunately no, I did months ago but I didn't realize how good she was in pvp and used her to up arbiter:

Sadly, you're very much going to struggle in that case. My best advice:

1. Arbiter (lead) -> Khatun -> Serris -> Magnarr, DON'T run this against their speed nuke team. Run it against their go-second team team. Build Serris with >500 ACC, and hope that you don't get cut-in
2. Yumeko (fastest) -> Visix (second fastest) -> Uugo (slow af) -> Shazar (lead, even slower than Uugo), DON'T run this against their primary speed nuke team, run it against their second speed team, and just hope your Yumeko is faster than their speed lead. The goal here is for Yumeko to shut down their cooldowns, and then Visix to provoke, and then to wait until their Stoneskin etc run out (since Yumeko's A3 ignores Stoneskin) so that Uugo can do her block buffs and then Shazar can finish them off with his bomb.
3. Tuhanarak (fastest, give her a Frenzy set and the Timely Intervention mastery), Scyl (Freeze set), Aniri (Freeze set), Drath (Freezet set). Just try to keep reviving people and outpace their damage. Run this against their speed nuke team and pray that Tuhanarak gets boosted by their Lydia or Deacon or etc, and can remove the debuffs before their nuke goes off.