While I disagree w/the idea that aligning both the marks at 12 o'clock and sighting across the cam gear w/a straightedge is any better than the usually recommended way of doing it- especially on an assembled engine sitting between the fenders of the vehicle (like the OPís situation if I understand it correctly), to each their own. If it works for YOU, that's what matters. But it is not a procedure I will be recommending for the simple reason that it introduces more chance for error than it prevents- IN MY OPINION.
But more importantly IMO is regardless of the method of aligning the marks- putting them at 12 and 12 and straight edging, or some other non-traditional way of aligning the marks, or doing it the normal way- I recommend that the engine be turned a couple revolutions after aligning the gears to see that the alignment of the dots on the gears is correct.
This can be easily done either just to check the gear alignment or during the course of setting the valves- all it takes is one close look and you know if itís right or not after turning the engine over. This is Timing Set 101 stuff!