I recommend the threadstarter to just try it
Football tackles are especially useless as they lack the refinement of a defending opponent in a fight. Its just brute running down and that gets you nowhere 99% of the time.
You can see that very good in youth wrestling were you have muscular powerhouses with little skill who get countered into oblivion. There are many counters to someone running you down.
-roll back with the attack and use the velocity to land on top. Rockhold did that several times. Called Sutemi Nage in some japanese ma. Very effective.
-shifting weight and use the attackers momentum to throw him
-straight knee him in the head (mma)
-push his upper body even further down only to counter with a level change when he gets back up.
-pull one of his arms away with a diagonal backstep. Perfect opportunity to get an upper body takedown yourself.
-time an uppercut ...etc and much more
Thing is, you will not be able to take an experienced wrestler down with such an attack. You may not see it but there are often several directional or level changes and feinting before even the best wrestlers can execute the takedown. GSP wasnt only the best mma wrestler because of his speed and strenght but because he changed the his forward momentum constantly to the opponets weak balance points.
Brock is a good example. He ran down Herring but did not win one iota in position. Or look Brook vs. Cain. Brute force that got clubbered into submission