volodnya, I don't think that is quite accurate. AFAIK, the game engine neither knows nor cares how many mods you have activated. All the game engine sees is a set of files that it uses to control its execution. These files always have the same filenames. Whether the files have been replaced or changed is transparent to the game engine.
Activating many mods does increase the risk of mod-to-mod incompatibilities. Mod A changes File X. Mod B does not change File X (so there is no overwrite alert from JSGME), but it does change File Y in such a way that the game engine now needs the stock version of File X to run properly, not Mod A's version. The result is unpredictable, and probably not good.
That said, a mod list can be pretty huge (100 or more) and still run perfectly well, as long as all the mods keep out of one another's way. But the only way to know whether mods are compatible is to activate and run the successfully. And with a big mod list, that can be a slow tedious process.
You are safest using a published mod list. Hopefully, the poster has done his homework and made sure the list is completely compatible. (If he hadn't, the screams on SubSim would quickly let you know.
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