Depends on your continuity and who was drawing them that day!
Fort Max is supposedly bigger than Metro in the cartoon and certainly in the toy version, AFAIK. The Marvel version started off a little above-average and was retooled to much larger than regular TFs, but not city sized. I can't remember which way Dreamwave went, but I'd suspect they followed the 'toon.
Scorponok is of a similar size to Max in both the comic and the 'toon, probably similar to Trypticon, who likewise is more battle station than city sized in the comics.
As an aside - for Metroplex, the comic explanation was that he was part
of Autobot City rather than the entire city itself, which makes much more sense to me.
See also this image from the Japanese Headmasters series
, which makes absolutely no sense when you look at the relative sizes of Chromedome and Fortress (either the boxout pic or in head mode).