Got a nasty cold, stayed home, and played the hell out of this today.
In
Dead Rising 1, it never seemed smart to give anyone a weapon. Just clear a path for them and mash the "FOLLOW ME" button like crazy. Survivors in
DR2 shoot better than I do.

spoiler (click to show/hide)
I had the "Tastes Like Chicken" mission earlier, failed it the first try; luckily it was right after saving.
After a real-world nap, I tried it again. The "Trail of the Money" (or something similarly named) mission had a bunch of mercs running around, so I dropped in on them, grabbed one of their machine guns, and went in search of a Survivor. He dealt with the psycho, and then I had two Survivors with merc machine guns. They pretty much dealt with "Everyone Knows Slappy" on their own, and were easily pulling their own weight during the remainder of the 4-part mercs' mission. I came REALLY close to losing them during the Slappy confrontation, so I decided to turn them in to the Security Room.
First I traded them some booze for their weapons though, so I can hand the merc machineguns to the next Survivors. Hell yeah.
Oh, hey, it looks like you can refill any guns by handing them to a Survivor. It may be my imagination, but it seemed like whenever I handed them healing items, they'd hand me back the ranged weapon they're carrying with a full clip.
Just got this 
You will not be disappointed.