I ran nine frames and I ran ten frames in standard boxes on many thousands of hives in single broods and in double or even triples.  I never saw any difference in production or winter survival .

I even ran eight frame broods occasionally by accident when a swarm decided to move in above an excluder.  I would not recommend it.  

I tried eleven frame broods as some recommend, but that is very fussy and pointless IMO.. It only made beekeeping difficult for me and maybe the bees, however some swear by it, so to each his own.

As for Ross Rounds, I produced many tens of thousands of rounds and never found any swarming issues I could attribute to the practice. even though I sometimes had to crowd the hives after swarming season to finish combs .

Swarms happen occasionally no matter what we do.   Swarming seems to be a result of convergence of many factors.  Even tiny mating nucs can swarm. 

That was my experience, in my area, and with my management schemes so others experience is bound to be different.

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