Allen was an artist down there. He alway picked the right hole and approach (high leap, submarine, bounce outside, cut inside).
Csonka was the premier power only back in my lifetime. I never saw Bronko Nagurski play (thank god I'm not that old) but I imagine Csonka must have been similar in his ability to carry tacklers while simultaneously running other tacklers over.
For those that remember Mike Alstott, Alstott couldn't hold a candle to Csonka.
I would add that my recollection is that John Riggins was a great goal line back.