The Quadra 630 came first and its form factor and case design are right on as I see it. It came at a time when 17" CRTs were standard for business use and its metal chassis could support monitors well beyond what the injection molded cases of the Macs you've mentioned were rated. The one exception to that injection molded case limitation is the exceptional DuoDock with its elephantine support legs that was rated for 21" Color CRTs.
AV Macs that came before were counterfeit "Pro Models" that couldn't hold a candle to professional NuBus Content Production Workstations. The Quadra 630 and is offspring were designed from the ground up as consumer level AV machines with two brand new slots alongside the venerable LCIII PDS of the old low end Quadra 605/LC 475. They didn't bother with the iffy stereo speakers in the 5xx series for the 630 because by then everyone had adopted "computer speakers" that at their cheapest were higher quality.
That ModularMedusaMess construction is a lot more practical with the slide in motherboard than anything from the Mac II or Quadra lines. The metal chassis is rugged as hell and a breath of fresh air after the horrid 8xx case.
Yep, I got along with lower end Macs because I didn't need color or tremendous power doing object oriented graphics. The Rocket in the IIx worked great all through the Quadra era. I got the Quadra 630 as backup for that production machine, as my kid's AV/HomeWorkStation and for me to use as needed after he fell asleep. I wouldn't have set the 17" Trinitron Monitor/TV from the kiddo's Quadra 630 setup on top of my IIx/Rocket or the Quadra 605 I got later as a toy. That one got the Portrait, but that's another story.