What's wrong with the deer rifle you plan to actually hunt with?
Being alert, making smart choices, and paying attention to the landscape around you will often alleviate the vast majority of grizz encounters.
The ones you can't avoid, you handle best you are able in the moment. Have a plan at the ready knowing the planning is likely more valuable than the plan itself .
If y'all are rolling three deep, all with firearms, I see little need for specialized armament. Yes there are plenty of grizz, but no they aren't behind every tree waiting to pounce on unsuspecting travelers.
If the 30-30 or AR10 is your deer rifle, take that one. If one of those is your backup deer rifle, take that one. In the event of a life threatening encounter, a howitzer might seem puny in the moment.
Be reasonably prepared, but there is little need for paranoia. All paranoia will bring you is a greatly reduced experience with increased anxiety.
Be reasonable, use some common sense, enjoy the hunt, and good luck.