Yes. 750,000+ people per Representative is ridiculous.
And an unwieldy body of 6,563 Representatives wouldn't be?
There's a middle ground. 1000-1500 members should work fine, given a strong hierarchical leadership and committee system (which the US Congress already has).
What's the point though? I get the argument for the Wyoming Rule to minimize population variance between districts, but after that, it seems like you're just adding representatives for the sake of it. I don't think there's anything more democratic or effective about having a rep for every 300,000 instead of every 600,000 people.
Thats why you use the cube root rule.
That keeps the representative size increasing as our population increases but at a reasonable rate.