It really applies to nobody. The Logan Act might be the most ignored and pointless law in US history. Even stuff like Operation Red Dog was prosecuted under a totally different law.
Of all the Not Happening in stuff Trump could get prosecuted for, this is the most Not Happening.
Nixon did it with the Vietnam War. Reagan did it with the Iranian Hostage Crisis. Trump did it with Putin in 2016 (and then Pardoned Michael Flynn for taking part in it).