The photo of the Arrow crank in their listing...the crank has 3 holes. Two are the factory holes with one drilled in the center of it.
Smolik Performance has a YT video showing how to drill one additional hole per side.
I tried this exact thing but didn't get satisfactory results. My vibes were still unacceptably high.....but I did not use the crank with a stock top end.
It wasn't until I did the balance factor method and ended up with 5 holes per side that my vibes went way down.
Arrow does state in the listing, "balanced and lightened" so that may be a thing.....or the lightening could just come from the material removed from drilling the hole.