I'll take a shot.
By your definition a lot of games created, marketed and sold as new games would i guess just be mods. As far as i know Tiller's doesn't create content anymore, his engine is used in Panzer Campaigns, Panzer Battles, are these games just mods, or not because there sold under the Tiller banner. Panzer Battles is created by another dev using a modified Tiller engine but its OK because its sold on the Tiller site? I guess i just don't get why single out these games, namely CSME and CS Vietnam. Basically almost any continuation using the same engine would be a mod by your definition or is it just when a company other than the original creator of the engine does it? AGEOD engine was used by another dev to create games using there engine, are those mods, well they were sold as new games. A lot of games use the same engine for continuation of a style of games or series. They change the graphics, maybe add features to the engine, sounds, ect. they are then sold as new games. I just don't see the difference when compared to the CS games.
Another point, what about dev's that just license other people's engines, are all those games mods? Unreal engine, Unity, what ever engine ID is selling, i mean there just building on someone else's engine. however you want to categorize games or mods is up to you, it just appears that your not really applying your definition equally and are singling these games out for some reason.
Thanks for the discussion
Enjoy when you can, and endure when you must. ~Johann Wolfgang von Goethe
"Be Yourself; Everyone else is already taken" ~Oscar Wilde
*I'm in the Wargamer middle ground*
I don't buy all the wargames I want, I just buy more than I need.