Let's say Mike could've pay those 11 people (meaning I'm also insisting all them being alive) without any incidents: no DEA, no Walt's deal with Jack & so on. That's why it's hypothetical.
Now, for how long could he buy their absolute silence? A year, a year and a half? Because 5 million $ doesn't cut it for 11 persons sentenced +8 years in prison. Bring your calculator and do the math: 15k * 11 = 165,000 $; 165k * 12 months =1,980,000 $/year.
Not to mention his money left for Kaylee. That's probably 2 million left, to her, as before Hank and Gomez RICO'd Gus' offshore accounts.
Any clearance, any misobservations that I haven't seen?