Difficulty Settings

I've been playing Dead Rising 2 a lot recently and the difficulty of the game is starting to get frustrating. The problem I'm having is there are 'boss' fights that exist as part of the plot and as part of rescuing survivors and these fights are brutally hard. For the most part they all seem to have a powerful ranged attack which has a knockdown component making it practically impossible to aim a gun at them and powerful melee attacks which make it hard to swing any sort of awkward melee weapon at them without taking a beating in return. They kill me in 3 or 4 hits. I have to hit them 20-30 times to kill them and it has to be with a powerful weapon like a katana, sledgehammer, or lightsaber. They move faster than I do, can't be stunned or dazed, and knockdown even with their melee attacks. The only advantage I have is I can heal by eating food in the area or that I brought with me and they can't. (Except one guy who actually spent most of the fight eating. I have no idea how to even try to beat him since he healed to full every 10 seconds.) Also they're AI controlled so if there's a trick that can be exploited I may be able to exploit it. The problem there is when I first get into a boss fight I tend to be dead in a matter of seconds and the nearest save point was probably a 5 minute run away.

Now, every time I level up I get more powerful. I can do more damage with my attacks, or get more max health, or get the ability to carry more items (which means more healing items or powerful weapons if I prepare in advance) or get more abilities. I remember in the original Dead Rising that I gained the ability to dodge by rolling away at one point and that ability would be crucial for many of these fights. Get in, melee once or twice, dodge the big attack, repeat. Instead of now where my plan is get in, melee one or two times, get knocked down while losing a third of my health, run in a circle until I find food, eat it, repeat.

Am I supposed to just ignore the boss fights and level grind? You can restart the plot from the beginning without resetting your character level so that's certainly a plausible way to approach things. Certainly the non-plot fights I've taken to just skipping but I had a mandatory mission involving a fight with two katana wielding babes and it took many tries before I final won. My winning strategy? Fill my inventory with broom/machete combo weapons and full health items. Blindly charge in and mash attack until I got knocked down. Heal when I got low. Repeat. I barely won. But there was no tactics involved. If they started attacking me I had no way to avoid the damage so I simply had to chase and burn them out first.

I like hard fights but these just seem so out of reach and not having saves anywhere near the fights is frustrating. I feel like the fights should scale with level in some way or I should have some sort of ability to use defensively. Right now it seems like whenever the AI decides to do damage to me they get to and my only hope is it just is designed to play badly enough to let me win. Maybe I should just grind up some zombies and see if I can't learn a dodge move...