I don't know what you mean by Carousel exactly.
My Idea for HoMM3, <font size="1">(sorry for me the third one is the only real one, have to add the <3> in a compulsive way <img src="smileys/smiley4.gif" border="0" align="middle" />)</font>
was to run a "While Loop" for a unit, where the unit checks the enemies X,Y and it moves accordingly.
X,Y and/or diagonal to the next Field that will bring him closer to the enemy.
And thx ^^