Couldn’t I just cut down my current set of irons to be the same length?

You could but they are not designed to do this.

You would have to add length to your higher lofted clubs as well as grind off weight. On the lower lofted clubs you would need to add a lot of weight.

You would also have to adjust the loft of the clubs to get the right distance gapping, but this could effectively change the bounce of your clubs and create a club that skips or digs too much. Then there’s the problem of achieving consistent peak heights with all the clubs.

On the other hand, the Sterling Irons® are specifically designed to be built with a single shaft length using a single ball position.