the more you look at it, the more I actually think Silvagni was greatest defender ever. To contend with all the greats forwards and not just hold his own, but often break even or beat them, it's not something many were successful at. For Silvagni, he relished the challenge.
Silvagni usually took the oppositions most important forward regardless of position and they were a diverse set - Ablett, Dunstall, Lockett, Carey, Hird among them. These guys are some of the best players I've seen and they all had uniquely different skill sets.
I recall in Hird's Brownlow year while getting shut down by SOS, he took himself into the midfield to try and get into the game. SOS followed him everywhere and continued the bath, was BOG and got 3 Brownlow votes. In the 99' GF SOS had Carey kickless to halftime and Carey did the same, but for some reason I'll never understand, Parko left Silvagni down back on Allison, despite him having won this very same kind of battle with Carey before.
Silvagni was more than just a FB, or all-round defender; he was a very talented footballer overall. Dunstall once rated him in the top 5 players he'd seen. He just had a few extra strings in his bow that other champion defenders didn't.