Well they always had Hale up there too as a genuine tall forward(second ruck) so it was actually 4 of them.Riewoldt and Lloyd were not particularly athletic, at least not more so than the average KPF.
As for Frankling, Roughead and Gunston I am not sure that is a great example and almost proves my point as Gunston basically played as a medium sized forward despite being 193cm and I could be wrong, and I am sure Hawthorn fans will correct me but both Buddy and Roughead spent a lot of time outside of the forward line during that era due to the fact all three could not play in there at once.