"No one is arguing that Scripture is not needed to be "thoroughly equipped."
The Protestant argument is that Scripture is sufficient (Sola Scriptura). This passage does not say that only Scripture is required.
See the difference?
I may say that gasoline is profitable so that the motoring man may be fully equipped for every good journey.
That doesn't mean i only need gasoline. I also need other things, like a car, a driver's license, a map, etc." [underline emphasis mine]
Okay n00b, you can stay ;o>
You can have eleventy jillion gallons of gasoline, but without a car, you will not be driving anywhere.