Wow. Is there any reason to be nasty and condescending? You posted here for answers and you got them, now you're acting like a tool because you didn't get the answer you wanted. Grow up.
There's a lot of things people would like to do 'for the coolness of it'. Thing is, some of these things just aren't possible. You seem to know how to mod, so you figure out how to mod the game to let you summon Durnheviir in Apocrypha if you're so dead set on doing so. Might break your game, but at least you'll have your coolness factor, right? Coming here to yell at us isn't going to help.
But guess what? Sahro doesn't fight. You hop on his back, you fly to Miraak, you land, Miraak takes his soul, you fight Miraak. That's it. There's no epic battle between dragons, and if you want that so badly, I really hope you're a damn good programmer to make a non-fighting dragon fight a summoned dragon in a fight that relies on the boss absorbing souls from any dragon in the area. And I still have to raise an eyebrow at the fact that you dulled down Sahrotaar - you equip Bend Will and shout it at him as soon as he lands. That, or he turns you into a Dragonbornsicle. It's not that hard at all.
Also, constantly calling us stupid because we're explaining in detail how and why you can't do something is very childish. It's like asking us how to walk on water and then calling us idiots because we've given you 9,000 reasons why you can't do it.
Although I do agree with you that this thread should be closed. You refuse to see anyone else's reasoning but your own, which makes this topic rather pointless.