Savage Opress and Pong Krell run a sabers-only gauntlet
Sabers only for everyone
Takes place on Umbara
Warm up: Zett Jukassa and Ezra
1: Nahdar Vebb & Dark Barriss Offee
2: Kanan & TPM Kenobi
3: Fifth Brother, Seventh Sister, Grand Inquisitor
4: AotC Kenobi and Anakin
5: Plo Koon and Agen Kolar
6: Grievous
7: DD Ventress and Vos
Boss: Dooku
Bonus Round: 501st legion
Assuming we're accepting Legends/Canon feats I'd wager 7 for sure. Plo has a power advantage over Pong, but it isn't by much and Krell's physicals, speed, and multiple saber staffs isn't something Plo has shown any sort of advantage over. Savage may be less inherently skilled than Agen, but it doesn't matter as Agen is inferior in the force and lacks the physicals to suggest he'd win a prolonged duel. Grievous would lose out to Savage's power in the force/Krell's ability to respond to his multi saber attack.
DD Vos can kill either of them, and Ventress can at least hold off Savage.