I use English almost daily at work, read books in English, and at home we watch DVD in original version. My wife likes English a lot and she speaks much better than me.
i can make illusion here because it's written English, but should you hear me speak,you'd guess I'm French after a few words .
I know that my grammar is not always perfect, but I have a lot of vocabulary. Good to exchange on forums like here, or also when I travel for my job: I know that I can speak about virtually any subject with the people I meet. Well, not with every one though. Few Mexicans speak more than a few words in English...
I agree with Didz about "consistency". This is very important, and actually why I started MoE. There were other mods adding units, but the style of the icons, or the name of units, or the stats, are not consistent and it gives a kind of inconsistent result which is not very good for immersion in my eyes.
Hence redoing the uniforms for every faction, using the same recruitment system for all, redoing all the icons so they all look alike, using the same naming convention (but trying to do everything in the local language is not always easy!)...
That's also why I won't try to make a Napoleon mod based on Shogun or Rome engine, even if they give more modding options. Because it would look very strange to have for example nice French uniforms, but fighting ancient Britons... Or to have good land battles, but galleys in the sea battle... Or Ancient buildings when fighting in cities...
A Napoleon mod with Rome engine means redoing EVERYTHING.
I'm impressed by people who try something like the Great War mod: a complete rework of the game to make it something it wasn't designed to do.
But this requires a large team of very skilled and dedicated people.
I'm less ambitious than that: I also want to make a complete overhaul for improved gameplay / uniforms / consistency, but at least within the general scope for which the game was initially designed.