If you don't want to die you are going to need more people, mainly because of the room before Mihawk. All the guys in 6/7 are low HP (5) high DEF units so you'll deal crab/turtle like damage. The elder sea horse can chain a random unit for 6 turns, and the rest will chain ALL the units of opposite color (DEX guy chains all STR units, INT will chain all PSY.. etc) for 6 turns. So, if you only have the captains and you don't kill the seahorse, the DEX guy and the INT guy in one turn (well, you can't do it), they will chain either Vivi or Laboon (or even better, both) and their captain ability will stop working (rip in pasta). That's only the first problem. The second issue is that they hit hard and with your pathetic HP you probably won't be able to take 2+ hits.To be 100% safe you'll need a full party where everyone has a combo of at least 5. If any of your crew members has a combo lower than 5 (coughArlongcough), make sure your team doesn't have more than 4 colors and only keep a mob that can't lock anyone.
Even if you make your way through all the mob stages with only 2 members (the die&gem $trategie), you won't have the 2.5 PERFECT chain multiplier so the battle will be twice as long.