Dude that's way too much ice. You're just watering down all that flavor you're paying for.
I mean, however you like it, you like it I guess. For me it's one ice cube per two ounces at the most, and that's only when I'm drinking cheaper stuff and don't care.
Interestingly, and perhaps counterintuitively, the opposite is true!
Because of the mass and decreased surface area touching the whiskey a large ice sphere (ice forms more densely at its core in a sphere) melts at a much, much slower pace than a small ice cube(s). That is the entire purpose of an ice sphere, to chill the booze without diluting it. I'm sure my son could also quote some formula for you about the fluid dynamics involved and how the increased surface tension of a sphere resists melting more than a cube, but frankly most of that goes over my head. My practical experience is that by the time I've finished my two fingers of bourbon, the sphere is still the same size.
I'm sure that if I let the glass sit there for a few hours (that's how long it takes one of these spheres to reduce by half) you would be right. I simply don't drink that slowly.