Obviously no, this is not OK.
Otherwise every company looking for nice civil war graphics for her game could do the same thing...
You can of course do whatever you want at home, but if you made such a work available to public, without formal authorisation from us, you could run into trouble.
Using our engine and our graphics to copycat one of our games, is getting close to the frontier in terms of modding.
It's not that I'm particularly worried about your work and your intentions, but I have to draw the line for everyone. Indeed, we may use the WiA engine to cover new periods such as the 30 years war. Imagine our reaction if someone came and said: "hey, I did a free 30 years war mod by stealing the graphics and databases from the free demo"...
Modding is authorised to improve our games, or import
new personal contents.
Modding our engine to cover new conflicts is authorised with previous agreement from AGEod (cf: 2nd Punic war mod).
Modding our engine to copy another AGEod game using old AGEod contents requests explict and previous agreement from us.
Please take contact with Philthib for all these legal and agreement matters.
Cheers,
Korrigan