They don't happen at random intervals. They happen all at once.
But they don't happen all at once; mixing occurs over more than one round, and inputs don't all occur at round 1. Your inputs might begin at round 1 (in the graphic), while Joe's inputs might start at 2, and Sally's at 3, and so forth.
Ah, you make my point for me!
Joe's start at 2. Pre-denominated as 1+1+5+10+10. Also, Joe is not a MN and it's obvious. He's actually sending something, so all that scattering of sigs can pretty much be ignored. Where the hell did he send it? We don't know yet. We wait. Or, if we're "investigating" we look forward on the old blockchain... To the block/tx where we see 1+1+5+10+10 assigned to something. Joe sent 27DRK to Somebody. If there was a sale on Silk Road 2.0 for 27DRK, we now "know" (government version of knowing something) that Joe is SR 2.0, or is a vendor on SR 2.0. We just keep watching that 27DRK... It arrives at an exchange! We get a subpoena! Exchange gives up the info. Aw, Joe was smart and registered with a tormail email address and used no real information. But, he did use someone else's real info to make it look good. In fact, Joe was really smart, and used someone's info that lives 1500 miles away, to whom he has no connection of any kind, and he looked up that address via TOR as well. So, this innocent person gets a knock on their door... They are very badly inconvenienced, but in the end, nothing happens, it's a dead end. Now the investigators are grumpy for being mad a fool of... The subpoenaed information does include something useful; Joe traded that DRK for BTC! Since the price is volatile, it is easy to find the exchange rate correlation, and BTC is way easier to trace. He sent it to CoinBase! Somebody is Joe's Self! Another subpoena. Joe now has a cellmate who thinks he's sexy...
What happened to Sally? She doesn't have anything to do with SR 2.0. She can barely install the Windows DRK client, much less wrap her head around TOR or ever use it... But for all we know Joe used Sally's address on that crypto-exchange, and she got her life all messed up by these jerks anyway. Maybe the mere accusation and days missed from work resulted in her getting fired in her right-to-work State? Do the guvthugs give a shit? No. Is there any recourse? No. She's fucked and she never did anything wrong.
Maybe the correlations didn't lead to any of the right people. Then a mess of completely innocent people got strung up even if they didn't go to prison... The government does not give one flying fuck about the difference between correlation and causation when it comes to fucking yo up just because they can and they get off on that shit. "You might beat the rap, but you won't beat the ride." Even if the Chiefs don't convict you, the Indians will make you suffer just because they are sadistic fucks who get off on it, and DRK gave them the excuse... DRK's protection is insufficient to guard against this.
Me? I decided to tumble on bitcoinfog. I was smart and I only pulled a random fraction out of the tumbler. I won't make another withdrawal from said tumbler until I first make a deposit. I always randomize my withdrawal quantities and timing. The quantities never add up. I always leave some change on the tumbler. And not just dust. Often large chunks. Sure, I had to trust them. But I've been using them for half a decade and they've never screwed me. Nothing wrong with trust. Even if bitcoinfog is run by the guv itself, nothing adds up because I also made my deposits and preceding withdrawals using the same principles. What guvthugs? Because my input timing was random and did not correlate, I was MORE secure using BTC than I was with DRK! Nobody has any fucking clue what happened because the ins and outs don't match, and none of it happened in any concerted timing. I left some coin hanging in multiple places, and it'll sit there getting mixed really good on shared wallets with zero taint as I wait for more sales to accumulate, and I'll scramble it all up again... The only one who doesn't get fucked, is the one guy that actually broke the law!
(I do not perform any illegal activities, it's just a qualified example)
So, the overall quantity can be correlated by sig. It's as if entry-point sends aren't denominated at all, even if they are. It still correlates.
As demonstrated, it still correlates and under the wrong government (which already exists pretty much everywhere) it can still fuck the innocent.
Hell, you don't even need the sig, that just helps. Since the MNs don't actually mix, they're essentially nullified from an anon standpoint simply because what goes in must come out, and it does so in a predictable and measurable manner.