That has happened to me for a second time in Alliance Wars, so I was wondering what might be the case here.
When I doulbe / triple / quadruple a hero color in Attacks for alliance wars, it seems that number of tiles for that color decreases significantly, especially on the starting board. In the first instance I did triple a color and received exactly one tile of that color on starting board. Today during the new AW, I have doubled again and have received 3 tiles spread across the board. On top of that, defence teams seemed to focus that color, but I might be wrong about that.
Two other members from our alliances reported similar events - 3 times to one of them and another 1 time for the other.
I have never encountered this on Titans, World Map, and Offensive Raids.
P.S. It seems if you double two colors on your team it wont happen.