Leading patterns are more about forward IQ than agility. If you don't have enough agility to change direction on the lead, you should not be on the ground.Kennedy is definetly agile for a man his size, I have seen him kick quite a few goals at ground level. Excellent at burning his man via leading patterns as well.
Hawkins probably relies more on his body positioning and brute strength but he has reasonable agility.
Dixon is really just big with half decent hands. Clearly a rung below the other two in my book.
Very tough gig to make it as a power forward in the AFL these days, you have to have a point of difference apart from pure size.