any good team for the kobimeppo 30 stamina that it's not a towel nami one?
i tried with a g3 + purple one...but i always "almost" win..but never do in the end
For an INT team, you could try something like Buggy/Vista, Krieg, Mr. 3, Sgt. Helmeppo, and BP Chopper or Broggy. The extra HP leaves room for better stalling, hopefully allowing for some matching orbs to be farmed in round 6, with an orb conversion burst left in the chamber afterwards, and a single extra turn from Mr.3 for mop-up. Possible Sgt. Helmeppo subs with big HP could be Thunderbolt Nami, Nico Robin, Hawkins, or even a Rainbow Dragon.
If you have Mihawk, Mihawk/Mihawk, Buggy, Broggy, Mr. 3, and Sgt. Helmeppo would be solid. Good combo of decent HP and big INT burst damage.
If you have good PSY units, Shanks/Shanks, Master Sgt. Coby, Mr. 2, Dory or Gaimon, and either GP or Impact Usopp could probably get through without issues. Trash Helmeppo with PSY damage, then RCV orb burst against Coby. The team HP is a bit low, though, so there'd be very little room for stalling for specials.
EDIT: Shanks/Shanks, Marine Django, Master Sgt. Coby, Usopp and Vivi might work. If you get crummy orbs going into Coby, Vivi -> Django will probably improve the situation and set up for Coby's special. You could also sub out Vivi for a RCV heal like Broggy or Gaimon.
This is all just speculation on my part, though, since I personally use other teams, but I think with a little luck these could squeak out a win.
What level should Mihawk be for a passable 30 stamina slasher team?
I'd say around Lv. 55, if backed up by other slashers around Lv. 50. Lv. 60-70 is better, especially if your other units are in the 30s. I tend to measure survivability by HP total, because to me, the number of turns I can survive to do a full team's worth of damage is more important than an extra 100 Attack here and there. 10-12,000 HP keeps things comfortable, leaving room for mistakes and lousy orbs.
For this current fortnight, having strong INT slashers like Mr.3, Broggy, and Sgt. Helmeppo helps out more than another 10 levels in Mihawk.