It's still possible to put them back on in the correct order, tighten to the right torque and them still find one or two loose cogs!
Reason? Many modern cassette hubs are quite light and soft material, the splines gets scored aand one of the cogs snaggs and is not fully butted against the next. Everything tightens-up but eventually the snagg breaks/wears and suddenly you have a loose cog. Also if not everything is fully cleaned when you reassemble it's possible to get a small bit of grit/crud between to cogs giving the same effect...
I have learned these things...