Powered Exhaust vent--should I seal the static vents to ensure intake comes from soffit?

[jimojimoQQ]

Hi,
Basically the subject line is the question--I've heard one roofer say he'd installed many powered vents but didn't touch the static vents.

But it seems to me that since the powered vents are going to be installed pretty close to one of the static vents--that would just create an endless loop of circulating air just within that few feet of space between the two--and never create a pull from the soffit vents.

I'm hoping to get a general feel from the community here to see what the best plan is. Thanks,
Jim