to be honest mate a fallow buck in the rut will take some pulling over , and when they face the dog 9 times out of ten your in there too getting it down , but once thier down and like you said before you keep their heads down your good. lol
The fallow bucks can be pretty tough too, I have seen a bullx dragged 1/4 mile across a field and then disappear into a wood and come back with a mouth full of fleck and nothing else.
one of my bull crosses i got at moment had her 2 top holders snapped off with a game fallow buck ,when i got to her in was throwing her round like a rag doll ,it charge