Not a stupid question and it can be done in TS2010, no script needed
In the textures menu, choose "fill grid". Grid is the default "asset to be replaced", drag it to the "asset to replace"
Now find all the textures you have, click on "get texture", and drag to the "asset to be replaced". The more textures you have, the more work involved, but you can always repeat for any you missed.
Make choices on "current section only" and "replace direction and scale"