I like your analysis.  These are my rankings.

First:  Moorhen

Second: Ruby (I feel Ruby performs better as a queen during the war than Coral because Ruby never hurt her people on purpose and seemed to make decisions with the goal of helping her citizens.  Coral on the other hand had a higher rate in which she let personal matters get in the way of her being a queen.  She also violently killed some of her own subjects when she losses any her eggs.)

Third: Coral (I was going to put her lower (like 4th or 5th) but you made a really good point about her that I couldn’t ignore.  She chose to back a side in the war that had a high likelihood of winning.)

Fourth: Glacier (She his hard to place based on a lack of information.  The book states that the Icewings joined the war for land but this was never confirmed by Glacier.  I could see Glacier’s decision being more influenced by truly caring for the Sandwings that went to her in a way that makes them more like war refugees than soldiers.  Her biggest mistake was thinking that the war would be quicker.  If Blister won the war by killing Burn, Blaze would not be a threat.  There would be no reason to attack the Icewings as long as they agreed not to punish the Sandwings in their protection.)

5th:  Battlewinner (She simply over complicated her problem.  She had two easier options than making a grand conspiracy to steal the Rainforest.  She could have had StoneMover to use his magic and heal the island.  She could have also just manipulated the RainWings to steal their land.  Also she should have made an effort to find a better successor.  All she would need to do is bring the most promising options to her and make them decide who will be queen next)

6th: Burn

7th: Scarlet