while I would prefer GOG, unless Stardock UNLOCKS workshop for their games (aka enter a url and download to a mods folder for GOG, something you cannot do at this point), GOG is second class as workshop content currently for gal civ III is STEAM ONLY.  I would bet the same for OTC. To Stardock: look at gog mix: "games with mods locked on Steam".  OTC and gal civ III are also listed in the GOG mix "games that treat GOG as second-class customers" as well.  It does little good to pay full price and get modding tools when GOG customers have 0 access to the workshop UNLESS they have family sharing with someone who has a steam copy, know which folder the mods are in, and move the mods out so GOG can read.