Can't spend to much more time helping here lol.
But the tilemap is pretty good at this.
Advanced Wars GRID Thread
Here is the .capx from that thread
Can can also use map and put image points on that map (see manual)
And then there is transparent sprites and a few others. Many ways to skin a cat, so they say. Depends on you and your outcome. The Tilemap is pretty cool, I've just started implementing it myself (newish feature) and I am complete noob, but it looks good.
The manual is one of the best I've come across for software, and suggest you read it, re-read it, bookmark, read, try everything as a test to see what it does. The best way is to do.
You haven't ever opened it So suggest you get busy on that.
Thanks, I have tons more, but with new forum lost access to them.