Staggs would go solid at fullback yes, but he's better used in the front line. With his aggression and stimulation he puts into his game closer to the ball the better. He is also quite explosive and you wouldn't want him to get exhausted from the extra running needed at fullback.
Bradman Best plays left centre .Let's not forget his fantastic defence either, Herbie consistently handles his opposite centre as well. Doesn't seem to matter who it is either. Big names like Ramien, Best, etc, Herbie makes it look easy.
He's easily the most well rounded back we have and a stud to boot. Maybe it's because he's more of a stud than Carrigan some people don't like him.....
His intro video on the Broncos web site is very passionate .