Board Thread:Versus Debates/@comment-34656247-20180726110937/@comment-26107879-20180728041040

Unless Hiruzen can use FTG too. He obviously knows it's functions since that's a jutsu coming from Konoha (Tobirama). Tobirama and Hashirama were his teachers. So if he met the physical and chakra needs to perform it, then there's no doubt he could use it.