So, using this with GCD is definetly NOT recommended?
Depends on how the script works. If it
actually switches the skill level of Spear and Longsword around, then it will mess with GCD due to the fact that GCD is always tracking your stats and will react in a broken manner if, say, a 30 Longsword stat suddenly becomes a 70 Longsword stat due to one-handed spears having to be considered Longswords to be one-handed.
I haven't looked at the script exactly. It sounds like a slightly more advanced version of the one used in the other mod - if you add the script, I guess - though in principle I suspect they work in the same way at the base level of functionality.
Granted, you could still use this mod with some slight modification. You'd simply have to remove the part of the script that is switching the stats around - in theory at least. Then you'd just have to deal with your Longsword stat being the basis for all one-handed spear combat which is a compromise that isn't too bad if you must have this mod/
Now again, I must
emphasize that I don't know if the script works in the same way. I think it does. Not sure though. And I'm not reinstalling Morrowind and the construction set just to find out. But I do think it's worth bringing up since GCD is quite popular and it might affect other leveling mods as well.