Well now that I have some experience in both of these areas, I feel I should chime in.
I would say, NO a 6-cyl cam is not a strong as a V8 cam. I know for certain that a steel rod small block will go to 9700 rpm 1-time.
When it gets there, it will break your cam into 3-pieces. Now, it may go to 9600 multiple times, I haven't tried that, but it will only go to 9700 1-time!
The little 6-cylinder didn't go anywhere near 9700 rpm, and it broke in 2-pieces.
So as you can plainly see,,,the V8 wins all the way around. It is better at breaking cams into more pieces, it has more cyls, and makes more hp.