If you simplify it to that degree, you could be correct. But you can't simplify it to that degree, and resolve the question as to whether or not the failure to win another SB after XXX is due to Jerry. And in say, 1996, at 32 years of age I doubt Stephen had as much input as he does now, at age 53, so what happened in the late 1990's may not be the same as what's happening now.
Put it this way, if Stephen and McClay and Garrett all said this draft "We need to draft Vander Esch in the first round if he's there at 19" and Jerry said "Ok, let's do it", then in the simple way you put it, yes Jerry made the "final" decision. But if Vander Esch flops, who's responsible? Again, in the simplest terms, it's Jerry.
In that instance Jerry did nothing but rubber stamp the decision of Stephen, et al. So any failure of Vander Esch is due in actual circumstances to Stephen, et al, but Jerry will of course be "responsible" because as I learned in college "You can designate authority but you can't designate responsibility".
But you can't use such simplicity to discuss how and why the Cowboys haven't been back to the SB or had much playoff success in the last 22 years, there's just more to it than who makes the "final" decision...