Issues Installing Gutters

Cut edges must have clean, crisp cuts in order to expose as little carbon steel as possible. The zinc from the anti-corrosive coating on the steel then will go into solution with hydrogen from rain water and be deposited on the carbon steel, protecting it. I'd really ask hard how they are going to make that clean of a cut. It sounds difficult. How far do the sheets overhang?

I have a home with a metal roof and I'm hoping to have gutters installed. One company told me that the roof was left "too long" on the edges and they would need to cut it back to allow even 6" gutters to function. They say they do this all the time. Another company told me that it was NEVER okay to cut the edges of the roof or it would rust and ruin the roof, and they would need to "build out" from the edge of the roof and attach the gutters further out to make them work. Who's right? I live in Michigan, so lots of rain and snow are inevitable, and I'll need covered gutters to avoid collecting thousands of acorns, if that makes a difference. Thanks!

That's great to know, thanks so much for your help!