I've been wrestling with this question. does the raw number of backlinks matter more than the number of unique domains linking to you?
Take two scenarios: 100 links from 10 domains, or 10 links from 10 domains. Which drives more authority?
A colleague put it best: links are like pylons carrying electricity - it's not the count but the power transferred. More links from the same domain doesn't multiply authority. Buying backlinks based on silly metrics like DA is a fool's game.
measuring true authority is nearly impossible. Tools claim to do it but I don't trust them. What matters more is whether the link gets visibility and clicks.
My approach: focus on earning genuine publicity. A link from a respected site, even if nofollow, is worth more than a pile of spammy ones. So domain diversity with quality beats link quantity every time.