Suggestions for 3 sisters-like planting

We really only have two critter pests here in the city: groundhogs and rabbits.  They are voracious though.   I did a few 3 sisters mounds last year and got only corn, which was great but the space could have been better utilized.  Any suggestions for companions with corn that the groundhogs and bunnies won't like as much?

I feel that the plants that groundhogs and rabbits don't like would not work for a 3 sister garden.

Maybe just plant corn and not try for the 3 sisters?

Cris is there any way to enclose a space?  I've been having critter problems as well. I don't have the time, money, or even desire to enclose all my beds, but I did 1. I think of it as my insurance plan.  I don't have groundhogs, but the person I copied the design from did. He didn't put anything on the top. One of the critters devouring my peas were birds, so I put deer fencing on top(an inexpensive plastic netting). The enclosure doesn't have to be fancy, I just felt if I had to cage my veggies at least it should look cool.
In a post I read here on permies a couple years ago Dr. Redhalk (I apologize if I messed up the spelling) said ammonia sprayed around the garden will keep mammals away. I wish I could remember what post it was in, but I don't have a clue.
Good luck to you. Don't give up, where there's a will there's a way.