I wouldn't say easiest, but it is preference and what your comfortable with. As your displaying above, lots of finger contorting to get those presses. In my layout, i have 1 button to hit for throw and 2 to hit for fatal blow.
Also once again, you ruin any chance of playing any other fighters if you go with the layout, these cabs are themed not dedicated, so you don't want to waste it with a static layout. I've seen pro-fighters use this 8 button layout as well, so it's not unheard of.
I'm able to pull off the same level of combos as some of the elite players no issue. Now say if someone says hay i need and want that layout no issue.
So honestly no right or wrong answer, still fun either way