Want some more proof? Here is a picture of two running shoes. The one on the left is one of my first shoes. I ran in it for about 300 miles. You don't need to be an expert to see that the shoe is worn in a bizarre way. My earlier shoes were even worse. I strike with the side of my heel and it shows. I had plenty of problems too. My first marathon I had a pretty bad psoas (groin muscle) problem and I had to walk 5 miles to finish. I have had knee and hip pain on and off. I usually get blisters on my feet. All these things have improved but they are still there. Especially when I don't train enough.
But I learned one thing: most matters are self-correcting. Not totally so, as you can see from the other shoe, a more recent one, and one I ran almost 1,000 miles in (I ran Boston with that shoe and had no problems). You have to look closer to see the wear pattern on that one, although it is still obvious. But the first shoe would never have lasted for a 1,000+ miles.
What you can't see very well is the left shoe is worn asymmetrically in front as well, whereas the right one is not.
I can tell you that my gait has improved significantly as well. And it all happened automatically because I kept running. No magic here!
So, forget about what the store people tell you. Forget about "types" of shoes. The best "type" of shoe is a light shoe. The lighter the better, because nothing matters more in running than weight. You need over 40,000 strides to run a marathon, and so you have to lift that shoe for over 40,000 times. Think about that before you buy.
Never buy a special shoe unless you have run for at least six months and problems develop that steadily get worse. Problems in this case are objective problems such as swelling, inflammation, etc. Pain is normal and some amount of pain should not deter you. Especially if you are late to the party like I was. If you have been running since childhood and develop pain, that is another matter. But if you start out late in life, you will suffer. There is no way around it. Even Lance Amstrong had to deal with shin splints.
There is a tendency for people to run to the doctor as soon as something hurts. Or to try to fix things quickly. And not surprisingly a whole army of "experts" stands at the ready to help. Ignore them! They don't know what they are talking about. Chances are they will make your problem worse.
Supporting a weak link will prevent adaptation. It may make the problem worse or shift it elsewhere. Your first response to minor issues should be to RUN MORE. Not right then and there of course, but after some relative rest. The cure for most problems is, more miles.